The invention discloses a corn straw total crop straw return protective farming method. A corn harvester with the straw crushing and returning function is adopted for harvesting during the autumn harvest in first year, meanwhile, the crushed corn straws are uniformly thrown into the field, and the ground surface is covered; ploughing and soil preparation operation is carried out; stubble ploughing, straw cutting and mix burying, subsoiling, soil preparation, compacting and the like are completed at one time; in the spring period in the second year, direct seeding is carried out, multiple worksuch as fertilization, precision seeding, soil covering, compacting and the like can be completed at one time; a nitrogen fertilizer is applied between the seedlings by a topdressing machine during the growth period of the corns. According to the method, the straw cutting segments are uniformly mixed in the soil of the tilling layer, so that the ground temperature can be improved, the straw rotting is accelerated, the diseases and pests are reduced, and meanwhile a certain surface straw coverage rate can be guaranteed, wind erosion and water erosion are reduced, and the purpose of protecting the soil is achieved, the method is especially suitable for being applied and popularized in regions with low winter and spring temperature in the northeast, and a technical support is provided for large-area popularization and protection of the regions.