Aimed at the seeding absence, a precision metering device assembled with automatic compensation seeding system was developed. A monitoring and controlling system was made to detect and compensate the absence seeding. As soon as the seed cell of the main meter is empty, the sensor will send a signal to single-chip-computer and the assistant meter will start to work for compensation at the right time. The results in the laboratory show that the system can work reliably, the compensation rate is more than 91%, the final absent seeding rate is less than 1.3%, and the placing precision rate of compensative seeds can reach 91.25%.  