16.5%。Traditional straw return implements slowly after the operation, and delays farming time, as well as, the straw burning causes environmental pollution. In light of the above problems, a fast decomposition straw returning machine which adopts the returning principle of combining decomposition agent spraying with mechanical straw shattering was designed. Field experiments show that straw decomposition rate of farmland when using this machine reaches 97.2% after 7 months, which is 17.1% higher than a single mechanical grinding treatment, and average wheat production is 16.5% higher than mechanical crushing method in the same area.