In view of the large demand for seed potatoes, the large amount of manual cutting, high labor intensity and low cutting efficiency, on the basis of adapting to the planting pattern and agronomic requirements, a directional arrangement of longitudinal and transverse cutting seed potato cutter was developed, which can simultaneously complete the tasks of seed potato cleaning, impurity removal, size sorting, directional arrangement of seed potatoes, slicing, potato block sterilization, seed fragments cleaning and collecting and transporting. The seed potato cutting machine performed the cutting operation under the motor drive. The key components included the seed potato sorting device, directional aligning device, longitudinal slicing device and transverse slicing device. The seed potato cutting machine adopted a combination of a longitudinal knife and a transverse knife to cut the block process, which can effectively improve the cutting efficiency of the seed potato and reduce the labor intensity. Taking the intermediate motor Ⅱ speed, the central distance between upper and lower rubber rollers and installation angle of potato knife comb as test factors, the response surface test was carried out with the qualified rate, blind rate and loss rate of seed potato as test indicators. The test data was analyzed by Design-Expert 8.0.6 software. To explore the correlation between seed cutting performance and various influencing factors and the interaction law, the optimal parameter combination was as follows: the intermediate motor Ⅱ speed was 965.76r/min, the center distance between upper and lower rubber rollers was 315mm, the installation angle of potato knife comb was 104.61°, under the optimal combination condition, the qualified rate was 94.86%, the blind rate was 1.84%, and the loss rate was 9.72%, and the verification test was carried out. The test result showed that the qualification rate was 92.13%, the blind rate was 1.91%, and the loss rate of seed potato was 10.21%. Compared with the optimized value, the relative errors of qualified rate, blind rate and loss rate were not more than 5.04%, which met the requirements of seed potato cutting. The research result can provide theoretical and technical reference for the development and improvement of seed potato cutter.