Abstract: To tackle the problems associated with the low release of nutrients and functional components in red kidney bean whole powder, this study employed a combination of microwave ripening and cellulase hydrolysis to process red kidney bean raw materials. The research focused on optimizing the processing conditions to enhance the nutritional and functional properties of the final product. Five key factors—microwave power, microwave time, amount of enzyme added, enzyme digestion time, and enzyme digestion temperature—were selected as independent variables. The dependent variables included average temperature, water content, dietary fiber content, total phenol content, and antioxidant properties of the red kidney bean whole powder. A central combinatorial experimental design was introduced to systematically analyze the influence of these factors on the target quantities. Additionally, the Hierarchical Analysis-Objective Hybrid Weighting (AHP-CRITIC) method, combined with response surface methodology, was applied to evaluate the interaction effects of the factors and optimize the processing parameters. The study revealed that the combination of microwave ripening and cellulase hydrolysis had a synergistic effect, significantly improving the nutrient utilization rate and functional properties of red kidney bean whole powder. Microwave treatment was found to enhance the efficiency of cellulase hydrolysis, leading to increased release of soluble dietary fiber, total phenols, and antioxidant compounds. This synergistic effect not only improved the nutritional profile of the powder but also enhanced its functional characteristics, making it a more valuable ingredient for food applications. Through the optimization process, the best processing parameters for microwave ripening-cellulase hydrolysis of red kidney bean whole powder were determined as follows: microwave power of 440 W, microwave time of 10 minutes, enzyme addition of 2.0%, enzyme digestion temperature of 55℃, and enzyme digestion time of 2 h. These optimized conditions resulted in a product with superior nutritional and functional properties. Specifically, the soluble dietary fiber content of the optimized red kidney bean whole powder reached 8.26 g/100 g, representing an 87.3% increase compared to conventionally processed powder. The total phenol content was measured at 485.58 mg/100 g, a 31.56% improvement over the control. The comprehensive score of the optimized product was 140.53 points, indicating its overall superiority in terms of nutritional quality and functional performance. The improvements in nutritional and functional properties achieved through this optimized process highlight the potential of microwave ripening and cellulase hydrolysis as effective techniques for enhancing the value of red kidney bean whole powder. The significant increases in soluble dietary fiber, total phenols, and antioxidant activity demonstrate that the combined treatment not only improves nutrient availability but also enhances the health-promoting properties of the powder. These findings suggest that the optimized red kidney bean whole powder could serve as a high-quality ingredient for functional foods, dietary supplements, and other health-oriented products. Furthermore, the study provides valuable insights into the mechanisms underlying the synergistic effects of microwave ripening and cellulase hydrolysis. Microwave treatment was found to disrupt the cell wall structure of red kidney beans, making the dietary fiber and phenolic compounds more accessible to enzymatic hydrolysis. This, in turn, facilitated the release of soluble dietary fiber and bioactive compounds, leading to the observed improvements in nutritional and functional properties. The results also underscore the importance of optimizing processing parameters to maximize the benefits of these treatments. In conclusion, this study demonstrates that the combination of microwave ripening and cellulase hydrolysis is an effective strategy for improving the nutritional and functional properties of red kidney bean whole powder. The optimized process parameters via. microwave power of 440 W, microwave time of 10 minutes, enzyme addition of 2.0%, enzyme digestion temperature of 55℃, and enzyme digestion time of 2 h resulted in a product with significantly enhanced soluble dietary fiber content, total phenol content. These improvements not only increase the nutritional value of red kidney bean whole powder but also expand its potential applications in the food industry. The findings of this study provide a theoretical foundation and practical reference for the development of high-quality red kidney bean whole powder products, offering new opportunities for the utilization of nutritious legume in functional foods and health-promoting products.