The invention discloses semen diluent and a method for artificial insemination of breeding hens at an interval of six days. The semen diluent comprises semen diluent 1, semen diluent 2 and semen diluent 3; the semen diluent is prepared from the following ingredients in part by weight: 5-7 parts of monosaccharide, 7.2-10.1 parts of buffering substance, 1.5-2.8 parts of antibiotics, 0.2-1.2 parts of weak electrolyte, 6.4-8.3 parts of vitamin, 0.3-0.5 parts of EDTA-Na (ethylenediamine tetraacetic acid disodium salt) or 1.5-2 parts of lycopene. The semen diluent is adopted for artificial insemination by adopting a six-day interval method, the sperm motility is effectively improved, the fertilization probability is increased, the labor intensity of workers is effectively reduced, the investment of labor cost is also reduced, and working stress caused by less breeders can be alleviated.