In order to solve the problem of Ethiopia tef mechanized seeding, a fertilization seeder for tef based on PLC was designed. The tef seeder mainly included seedmetering device, furrow opener, PLC control system and so on. Sowing speed was measured by speed sensor, and corresponding relationship between sowing speed and servo motor speed was established, which can be used to control servo motor speed to achieve the same seeding rate per unit area at different sowing speeds. A small seedmetering device and singledisc opener were designed to solve the problem of poor uniformity and low stability. The PLC control system was designed for sowing, which can assure the tef seeder worked well in clay soil. It would be easy to adjust seeding rate and fertilizer rate through humancomputer interaction interface. Seedmetering device performance experiment was carried out at different seeding rates of 4kg/hm2, 5kg/hm2 and 6kg/hm2 and sowing speeds of 3km/h, 4km/h and 5km/h. The results showed that the consistency variability coefficient of row seeding quantity was decreased with the increase of seeding rate and sowing speed, and the stability variability coefficient of full seeding quantity was decreased with the increase of seeding rate, which was firstly increased and then decreased with the increase of sowing speed. When the seeding rate was 5kg/hm2, the consistency variability coefficient of row was 5.02%, stability variability coefficient of full row seeding quantity was 0.89%, seed damaged rate was 0.1% and seed uniformity coefficient of variation was 18.9% under zero level testing condition, which can meet the standard requirements. The sowing uniformity coefficient of variation was 20.4% in field experiment, which can meet tef agronomic requirements.