The design idea of the overall structural design, the rotary cutter and the drive system of the whole rice straw returning machine (1ZT-210) was expounded. Field experiments were conducted and the results showed that straw returning could improve the physical properties of the soil, change the components and characteristic of the humus in the soil, regulate the temperature of the soil and protect the soil. The results also proved that the reversing straw returning machine with a grass fence was perfect in turning the soil and covering the straw and featured good soil plough horizon after the tillage; the tillage depth was 18 cm and more than 95% of the straw was covered beneath 15 cm. The whole rice straw returning machine is advanced, practical and feasible and could meet the demands of the protective farming and guarantee the quality of rice transplant.