To detect potato metering device performance index and seeding accuracy index,the potato seed metering device performance testing system with sanding,metering,transmission,control and image processing was designed and the corresponding detection method was put forward.The metering device is fixed on the test bench,seed falls on the moving conveyor belt,and industrial camera shots video of the potatoes on the conveyor belt.The key frames of the video are determined and extracted according to the motion parameters of the conveyor belt and the frame rate of the camera.By identifying and locating the two-dimensional code pasted on the conveyor belt,the key frames are stitching to get all the potatoes without repeated images in one test.The image of seed potato was processed and analyzed.The central coordinates of each kind of seed potato were obtained.The relative position information of the seed potato was calculated to evaluate the performance of the seed metering device.The results showed that the detection system has high measurement accuracy,greatly reduces the labor intensity and has a good application value.