Abstract: Poria cocos is the dried sclerotium of a fungus in the Polyporaceae family. It often parasitizes on the roots of Pinaceae plants and is a commonly used traditional Chinese medicinal material in China. After harvest, poria cocos needs to undergo appropriate primary processing at the origin before it can be used as Chinese herbal decoction pieces. Currently, the primary processing methods commonly used in the main producing areas of poria cocos include static sweating, steam sweating, and pharmacy sweating. Among them, static sweating, as a traditional process, has deficiencies such as a long processing cycle and high labor intensity. The steam sweating method is becoming increasingly widely used due to its potential advantages in processing efficiency and yield. Static sweating can significantly increase the content of water-soluble polysaccharides and improve their solubility, but the content of triterpenoid components decreases significantly. Steam sweating leads to a significant decrease in the content of water-soluble polysaccharides. Therefore, which pretreatment method can maximally retain the medicinal components of poria cocos while considering drying efficiency and product quality remains a key issue that urgently needs systematic research. To clarify the primary processing methods of poria cocos at the origin and improve drying efficiency and quality, this study screened out the optimal sweating method for poria cocos pretreatment, and explored the vacuum pulsation infrared drying characteristics and quality of poria cocos cubes. Poria cocos was pretreated by three methods: static sweating, steam sweating, and pharmacy sweating. The moisture content and water-soluble polysaccharide content after pretreatment were analyzed. After sweating treatment, poria cocos was cut into cubes of 8, 12, and 16 mm. Under different vacuum times (2, 5, 10, 15, 25 min) and different atmospheric pressure times (2, 4, 8, 12 min), its drying characteristics, crushing rate, shrinkage rate, color, and water-soluble polysaccharide content were studied. The results of the pretreatment indicated that during steam sweating, the moisture content of poria cocos peels remained unchanged, while that of red poria cocos and poria cocos changed from 49.87% and 51.95% to 52.57% and 53.84% respectively. However, steam sweating led to the inactivation of the mycelium of poria cocos, preventing secondary growth. During static sweating, the moisture content of poria cocos peels, red poria cocos, and poria cocos all decreased. During pharmacy sweating, the moisture content of Poria cocos and poria cocos peels gradually decreased, and the moisture content of red poria cocos at the end of sweating was higher than that of static sweating. Both static sweating and pharmacy sweating involved a secondary growth process. The water-soluble sugar content was the highest after 3 days of pharmacy sweating, making it the optimal sweating method. The vacuum pulsed infrared drying test results of poria cocos cubes showed that the drying time increased first and then decreased with the increase of vacuum time and normal time. The smaller the size of poria cocos cubes, the shorter the drying time. The smaller the size of poria cocos cubes, the higher the breakage rate and the lower the shrinkage rate; the larger the size, the lower the breakage rate and the higher the shrinkage rate. The brightness (L*) decreased first and then increased with the extension of vacuum time and normal time, and the content of water-soluble polysaccharides increased first and then decreased with the extension of vacuum time. When the size of poria cocos cubes was 12 mm, the vacuum time was 10 min, and the normal time was 4 min, it could achieve a high drying efficiency and dry product quality, with a breakage rate and shrinkage rate of 22.45% and 25.42% respectively, L* of 53.25, and a water-soluble polysaccharide content of 35.21 mg/g. This study identified the optimal sweating method for poria cocos pretreatment and determined the optimal vacuum pulsed infrared drying process, solving the problems of low efficiency and difficult quality control in traditional drying methods, and providing a specific and feasible technical solution for the modern and standardized production of poria cocos.