The penetration effect of reactive fragment on medium thickness aluminum alloy target aimed at was studied. An experimental equipment was designed in order to study the penetration of single reactive fragment with different impacting speeds, and the pressure propagation process of reactive fragment penetrating aluminum target was simulated using the finite element analysis software of AUTODYN-2D. The results show that Al/PTFE reactive fragment possess the double damage effect from both kinetic energy and chemical energy under the condition of high speed impact. With the impact speed of 1,346 m/s~1,645 m/s, the fragment could occur and ignition energy release, forming the hole of 3.41 mm~6.51 mm on the thick aluminum alloy target of 20mm. Based on the experiment, the numerical simulation results fit quite well with the experiment results.