Abstract: For solving the problems about automatic testing farming quality and quantity of large scale precision seeder, seed and fertilizer farming intelligent gauging and monitoring system was studied and designed. It can gauge the seeding rate and fertilizer rate, and monitor the blockage of seed and fertilizer spouts, or the emptying of seed and fertilizer boxes. Compared with the past study methods, the differences of the study were: it used indirect method to gauge the seeding rate and fertilizer rate, and to gauge farming area by two-wheel testing distance method. And photoelectric sensors array were used to monitor the blockage of seed and fertilizer spouts, and the emptying of seed and fertilizer boxes. It was installed on the 2BJM-9 precision seeder, and experimented in farm. The relative errors of seeding rate, fertilizer rate and farming area were less than 5%, 9.6%, 5.5%, respectively. The maximum relay time of alarming was 0.8 s. Field trial showed this method was practicable, and the monitoring effect was better. This system can realize to monitor whole course of precision seeders operating in all-weather.