Abstract: Affected by friction of structural components of seed metering device, seeding volume of wheat seeder will have certain fluctuations during seeding operation, so when closed-loop control of seeding volume is carried out, it is usually due to a lack of effective detection of dynamic seeding volume, which leads to poor control accuracy．So, seeding volume automatic closed-loop control of wheat seeder under seed discharge shaft rotational speed feedback was proposed．Mathematical modeling of wheat seeder was carried out by constructing line voltage equations and motor motion equations, and differential equations were used to describe dynamic relationship between motor and seed discharge shaft．A weighing sensor was installed between seed box and suspended side plate, and weighted filtering results of sensor's measurement signal were combined to monitor mass change of seeds in seed box in real time．Combined with digital signal quantity of dynamic seeding measurement results, seeding error was calculated, and combined with PID controller, control quantity was calculated, so as to adjust rotational speed of seed discharging shaft and realize closed-loop control of seeding quantity．In experiment, control accuracy of proposed method was tested．Results showed that after proposed method was used to control seeding volume of seeder, empty hole rate of experimental field was low, and control accuracy had a more ideal．