According to the topographic characteristics of Yunnan hilly and mountainous areas and the working environment under sloping farmland conditions, a double-crank five-bar cauliflower pot seedling transplanter planting mechanism was designed. Through the analysis of the five-bar mechanism of the transplanter, the length of each member of the five-bar mechanism was determined, and the mass moment of each member that met the inertial force balance condition of the five-bar mechanism was obtained based on the linear independent vector method. Combining the image processing function of Matlab software to design a punch that matched the contour of the pot seedling. The RecurDyn and ANSYS simulation software was used, and the planting trajectory of the planting mechanism and the structural strength of the punch were analyzed. High-speed photography was used to verify the planting trajectory of the five-bar mechanism. According to the simulation results, the planting performance bench test of the planting mechanism was carried out. Taking the advancement speed of the bench, planting frequency and soil depth as experimental factors, a mathematical model of the planting qualification rate, the rate of exposed seedlings and the coefficient of variation of plant spacing was established. Response surface method was used to optimize, the best working combination was obtained as follows: the advancement speed of the platform was 0.4~0.54m/s, the planting frequency was 50~68 plants/min, and when the soil depth was 10cm, the planting qualification rate was greater than 90% and the seedling exposed rate was less than 5%, the coefficient of variation of plant spacing was less than 5%. Set the forward speed of the cauliflower pot seedling transplanter unit to 0.52m/s, the planting frequency of cauliflower pot seedlings was 61 plants/min, and the penetration depth of the puncher was controlled at 10cm. The filed test was carried out. The results showed that the cauliflower pot seedlings were planted. The qualified rate was 91.67%, the seedling exposed rate was 3.33%, and the coefficient of variation of plant spacing was 4.17%, which met the agronomic requirements for cauliflower pot seedling transplanting.