Considering the problem that there is short of test platform that can systematically test the operation parameters and performance indexes of the key components of the planter, a performance test platform of key components for planter was developed. The working process of the platform was described. Meanwhile, the structure and key parameters of the seed and fertilizer quantity detection system, air supply and test module, ground wheel drive module, three-point suspension module, hydraulic power module, and display and control system were determined. The motion frame for simulating land slope was designed based on Stewart type parallel structure. The test results of no-load and working performance of each system module of performance test platform of key components for planter showed that the platform could realize seeding and fertilizer discharge signal, and seed and fertilizer quality detection in the 8-way seed guiding tube and fertilizer guiding tube in the process of seeding and fertilizer discharge. The platform could provide conveying air flow of 1.6992~2.5575m3/h when the rotating speed of seeding shaft and fertilizer discharge shaft was 20~120r/min. At the same time, the platform could test the air pressure and flow in the seeding and fertilizer discharge links, and the rotating speed and torque of the transmission system of the planter. The influence of -5°~5° land slope on the seeding performance of the planter could be simulated through the motion frame. The deviation rate between the tilt and reciprocating swing angle set by the motion frame and the tilt angle measured by the angle sensor was 0~0.25%, the deviation rate of reciprocating swing angle was 0~0.275%. The platform worked stably and could meet the test requirements of seeding and fertilizer discharge performance with different displacements.