Wheat precision seeding test system is designed to develop a measurement device of wheat precision seeding with high efficiency and precision. The wheat seeds are falling from the seed sowing device to the conveyer belt. Using image processing techniques, the system gets the pictures of seeds on the belt. Then these pictures are processed and analyzed to calculate the qualified rate, reseeding rate and leakage sowing rate, etc. This paper introduces the whole structure, design parameters of the system, the hardware and software of the image acquisition system. Through selection of a proper threshold, the method of seed identification and seed-space measurement are given in this paper.