Through designing dynamic tensile sample of PBX,selecting length of input bar and output bar,placing strain gauge in proper position,improving experiment methods based on properties of PBX which compressive strength was greater than tensile strength,it was realized dynamic tensile strength in the reflected split Hopkinson press bar (SHTB). It showed dynamic tests beared high tensile strength. Dynamic tensile strength of PBX attained 13 MPa in 30 s^-1 strain rate while quasi-static tensile strength was only 7 MPa. Through observed by SEM,quasi-static tension failure was different with dynamic tension failure because crack had different expand methods and temperature rise induced binder soften. Destroyed model in quasi-static tension was transcrystalline fracture and intergranular fracture and it was binder debonded in dynamic tension.