The invention discloses a mutation and screening method for salt-tolerant buckwheat mutants. The method comprises the following steps: treating and mutating buckwheat seeds by adopting EMS (Ethyl Methyl Sulfone), screening buckwheat mutants insensitive to ethylene by virtue of a direct precursor ACC (1-aminocyclopropane-1-carboxylic acid) obtained through ethylene synthesis, cultivating the buckwheat mutants into saline-alkali soil with the salinity of 0.4 to 0.6 percent, screening salt-tolerant plants, planting harvested buckwheat seeds into the saline-alkali soil with the salinity of 0.4 to 0.6 percent, and further screening the salt-tolerant buckwheat mutants with stable characters. According to the mutation and screening method for the salt-tolerant buckwheat mutants, the mutants are easily obtained by mutation with the EMS, DNAs are less damaged by point mutation, and meanwhile, screening with the direct precursor ACC in combination with ETH is combined to screen the salt-tolerant buckwheat mutants, so that the mutation frequency is high, the target is clear, the screening efficiency is high, and can reach 10 to 20 percent, the operation cost is low, and the obtained mutants have stable characters.