In order to address the difficulty of monitoring small seeds during the operation of an integrated rape sowing machine in southern Jiangsu, a monitoring system for the sowing performance of a single seed precision seeder for rapeseed is designed based on PVDF bi-piezoelectric film. The system collects the operating speed of the machine through the encoder installed on the tachometer wheel of the seeder, and obtains the theoretical seeding spacing in combination with the set target seeding rate. The PVDF bi-piezoelectric film monitoring device is used to collect the number of rapeseeds. In order to filter the interference of machine vibration signal, a reference piezoelectric film is set up to eliminate vibration interference through logic operations, and the Schmitt circuit hysteresis principle is used to eliminate comparator jitter interference. The system uses the STM32F103VBT6 microcontroller as the central processor to calculate the performance indicators such as sowing volume, seeding speed, omission rate and reseeding rate by combining the set theoretical plant distance, the time interval between adjacent pulse voltage signals and the forward speed of the seeder. The test bench shows that under the conditions of 26.5-42.2 r/min seeding shaft speed, the system detects the seeding volume with an accuracy of 96.4%, the missed sowing with an accuracy of 95.8% and the resowing with an accuracy of 98.4%. Under the condition that the vibration frequency is 8-16 Hz, the system can detect the sowing volume with an accuracy higher than 95.2%.