To research the temperature adaptation performance of cast polymer bonded explosive (PBX) under the condition of shell restriction, explosive of component as HMX/HTPB/TDI was prepared, and five specimens were charged with the size of Ф20 mm×20 mm, Ф15 mm×65 mm, Ф100 mm×200 mm, Ф150 mm×300 mm and Ф200 mm×400 mm, respectively. In which, the latter three specimens of larger size were divided into two forms of "without defect" and with "pre-prepared defect". The change in internal damage, temperature and strain of shell external, and size, density, mechanical properties of the explosive was studied by temperature impact test and temperature cycle test of-55-70 ℃. Results show that after temperature impact test and temperature cycle test, there is not obvious thermal damage in the cast PBX and the original damage does not extend obviously. With the increase of specimen size, the time required to reach temperature equilibration via heating and cooling is prolonged and the change in high and low temperature strain reveals a trend of decrease after tests, the density of the explosive increases by 0.001 g·cm^-3 and the tensile strength and compressive strength increase by 0.12, 0.55 MPa, respectively.