Abstract: This article introduced a new seed spacing measuring method based on image processing and analyzing technology. This method was successfully applied in the performance test of seeders. It is capable of real-time parallel capture of the three seeders' seeding status by using the independent capture of the three base colors red, green, and blue of the colorized image. It is also capable of joining serial images by using image-matching techniques based on the signs. The error of the seed spacing is less than 2 mm.