According to the agronomic requirements of small plant spacing for transplanting of clustered varieties of Guizhou pepper planting suitable for machine harvesting, the ISEKI PVHR2 transplanter was modified. After reducing the minimum plant spacing of the machine from 300mm to 150mm, the trajectory changes before and after plant spacing reduction were analyzed. With the goal of reducing the size of the hole and taking into account of the spatial position relationship between the planting device and the whole machine, the opening and closing time of the duckbill and the posture when entering the soil and receiving the seedlings, etcetera, the rods of the planting device were optimized. The optimized simulation results showed that the size of the hole was reduced from 91.1mm to 66.3mm. The transplanting experiment on the film was carried out according to the optimized size, and the test results showed that the width of the hole was slightly smaller than the theoretical analysis due to the elasticity of the mulch. The optimized planting device had a hole size of about 60mm when the planting distance was 150mm, which met the requirements of use. 