Integrated Detector Dewar Cooler Assembly(IDDCA) has been widely used for IRFPA detectors above 256×256 scale.Dewar vacuum life has become one key indicator which restricted the detector performance.For a general construction of IDDCA,Dewar vacuum life was tested by several ways,such as helium leakage rate test,heat load test and high temperature accelerated test.Main influence factors of Dewar vacuum life were analyzed.Analysis results show that leakage and outgassing are two main influence factors for Dewar vacuum life.The technology improvement can well control Dewar leakage,and vacuum baking and getter can eliminate Dewar outgassing.The vacuum life of self-developed IDDCA is over 12 years.