In this paper, a biodegradable seed coating formulation was prepared, with the natural polymer chitooligosaccharide as the bactericidal component, polyvinyl alcohol and glycerol as additives. The effects of the chitooligosaccharide mass fraction, glycerol mass fraction, degree of deacetylation of chitooligosaccharide on seed coating blend membranes tensile strength, elongation, membrane permeability and other parameters were investigated. The results showed that the tensile strength and elongation of the blend membranes improve with the increase of chitooligosaccharide and glycerol mass fraction. The membrane permeability decreased with the increase of chitooligosaccharide mass fraction, but increased with the glycerol mass fraction increases. The best ratio of seed coating preparation: chitooligosaccharide 2 %, polyvinyl alcohol 4 %, glycerol 0.5 %, reaction temperature 45℃and reaction time 1 h. This seed coating has good antibacterial, sterilization, promoting seeds germinated role. Compared with blank experiment, corn seed germination rate is improved 21%. In addition, the seed coating can effective prevention pest and protection seeds, promoting seedlings healthy growth, increase crop yield. Compared with conventional beforehand sowing, yield of an acre can increase 32kg of using this seed coating to process cotton seeds.