Seed flow during sowing will affect the quality of sowing, which will seriously affect yield when blockage occurs. In order to realize the fast and accurate detection of the seeding quality of the airflow conveying seeder, an arc array seeding flow sensor based on piezoelectric ceramics was designed. Based on the analysis of the seed movement characteristics of the airflow distributor outlet, the sensing unit layout and the overall structure of the sensor were optimally designed; the seed collision experiments under different conditions were used to determine the structural size and material of the sensing unit; a signal conditioning circuit and a pulse counting circuit were designed to realize the online measurement of seeds and realtime transmission through CAN communication. The effect of airflow pressure and metering quantity on the detection accuracy of the sensor was analyzed using the airflow seeding test bench. In the normal working pressure range, the detection error and air pressure approximately met the linear relationship. Based on this, a calibration model for sensor detection was further proposed and bench verification was performed. The test results showed that the maximum detection error of the sensor was within 5% when the air pressure was 166Pa and the seeding rate was less than 170 seeds/s under the recommended operating parameters, and the accuracy rate of the sensors alarm for blockage failure can reach 100%. The system can effectively monitor the seeding performance of the airflow conveying seeder, which can help to improve the quality of seeding operations.