Flax Heiya 31 is a new variety bred for fiber use by institute of industrial crops,Hei-longjiang Academy of Agricultural Sciences. The straw yield of this variety is 6779.63 kg/hm2,which is 1.79% higher than that of the control variety Heiya No.16. The fiber yield is 1778.10 kg/hm2,which is 14.09% higher than that of Heiya No.16. The seed yield is 1002.67 kg/hm2,which is 11.37% higher than that of Heiya No.16. The total fiber content is 31.67% and the fiber strength is 263 N. The variety has strong growth potential,and drought resistance. The variety was approved as a non-major crop variety by the Ministry of Agriculture and Rural Affairs of the People's Republic of China on April 21,2024 with the registration number of GPD Flax (2024) 230006.