A testing device was designed in order to study the working principle of vertical plate seed-metering device, improve the intensive research and enhance its working performance. The video information of working process was obtained by using high-speed image technique. The working principle of this device was clarified by the current study through high-speed image technique and data analysis, and the concrete scheme was put forward to enhance its performance. It has important instructional sense for the theoretical and practical research of seeding-machine.