Abstract: Pneumatic centralized seed metering technology has been developing rapidly both in China and abroad due to its high precision, high efficiency, and low seed damage. In traditional straight groove wheel type centralized wheat metering devices, the amount of seed discharged is high when the groove wheel rotates to the groove and low at the ridge, resulting in pulsation during seeding. To address the poor discharge stability and uneven seed distribution caused by the pulsation of straight groove wheel type devices, this study proposes a staggered helical groove wheel precision centralized wheat metering device. Based on the seed metering principle of the outer groove wheel type seed metering device, the seed metering process was optimized by eliminating the seed-feeding layer to reduce inter-seed stress and seed damage. Building upon the enhanced uniformity provided by the helical structure, two groove wheels with helical grooves were arranged in a staggered configuration, allowing the two wheels to discharge seeds in a complementary manner. The seed flows of the two groove wheels supplement each other, ensuring phase complementarity of the dual helical groove wheel seed supply cycle, further reducing pulsation and achieving uniform seed discharge and stable seed rate. Through analysis of seed stress between teeth and seed population motion, it was determined that the helical angle and stagger angle are key parameters affecting discharge stability and seeding uniformity. The main working parameters of the centralized seed metering device were determined by dividing and calculating the seed-holding space of the helical groove wheels. Using the helical angle and stagger angle as experimental factors, and discharge stability and seed distribution uniformity as evaluation indices, a two-factor, multi-level simulation experiment was conducted using the Discrete Element Method (DEM) to analyze the influence of these factors and to identify the optimal parameter combination. The results showed that both the helical angle and stagger angle had significant effects on discharge stability and seed distribution uniformity (P < 0.05). The coefficients of variation for both discharge stability and uniformity first decreased and then increased with increasing helical angle, while they gradually decreased with increasing stagger angle. The best performance was achieved when the helical angle was 45° and the stagger angle was 20°, with coefficients of variation of 2.06% and 7.29%, respectively. Bench test results showed that the performance of the centralized seed metering device was only slightly affected by operating speed. When operating at 8～10 km/h, the coefficient of variation for discharge stability did not exceed 2.23%, that for seed distribution uniformity did not exceed 7.52%, and the seed damage rate remained below 0.056%. Compared to the traditional outer groove wheel type seed metering device, the average coefficients of variation for discharge stability and seed distribution uniformity, as well as the seed damage rate, were reduced by 10.14, 4.5, and 0.093 percentage points, respectively. Simulation experiments comparing the stress on seeds between helical and straight groove wheels showed that the inter-groove seed stress of the helical groove wheel was significantly lower, with peak stress reduced by about 50 percentage points. Further analysis of seed stress across different groove wheels and seeding stages clarified the mechanism by which helical groove wheels reduce seed damage. This study confirms the impact of staggered helical groove wheels on the performance of centralized wheat metering devices through experimental analysis, providing both methodological and theoretical support for the development and improvement of operational stability and uniformity in groove wheel-based agricultural material conveying devices.