A kind of precision seeder for rice seedling-growing tray made of paddy-straw was developed. The key factors which had effect on seeder sowing accuracy were tested and optimized. The proposed seeder could sow 3～5 seeds in each holl and accomplish subsoil covering, seeds sowing, topsoil covering and other processes in one working time. The results showed that sowing uniformity was 98.2%, the ratio of cavity was 0.01%, single grain was 0, and seed production rate was 420 trays per hour, which met the requirements of rice seedling-growing tray made of paddy-straw seeding. 