The temperature-humidity environmental tests under 5 MPa axial compression stress were applied to polymer bonded explosive (PBX). Results show that the mechanical properties of the explosive change obviously after the tests. The explosive density has no change under the conditions of 45 ℃, 65%RH, 5 MPa, while it decreases obviously under the conditions of 60 ℃, 80%RH, 5 MPa. In addition, the modulus and the compressive strength all decrease obviously in the early aging time after the temperature-humidity-load accelerating age tests，but they have no obvious change as the aging time goes on..