Compressibility of porous materials was considered, shock temperature rise effect on the dynamic strength of front jet was analyzed theoretically. Penetration test results show that the porous copper liner with 11.4% porosity has better penetration ability than the homogeneous one when the standoff distance is between 1.3 and 3 charge diameters (CD), and the maximum penetration of porous jet is 1.12 times than that of copper one. The temperature rise in the porous liner is much higher, which is helpful to decrease jet viscosity and dynamic strength and increase the stretching ability at low standoff distance.