The free to roll test,static force balance test and dynamic derivative test of 80°/65° double delta wing at high angle of attack are conducted in FL-23 high speed wind tunnel,which dynamic behaviors are forecast based on the static roll moment coefficients and dynamic deriva-tive.The results show that dynamic motions obtained on a double delta wing was free to rotate a-bout its longitudinal axis at different angles of attack.Different dynamic rolling motions inclu-ding the static stability,double periodic oscillation,quasi-limit-cycle rock motion were observed. The forecast results meet the free to roll result well.