The method of evaluation of VDMOS storage failure rate is presented and explained in this paper. To obtain a large number of devices working hours in a short time, the accelerated factor k is brought into the failure rate test, from which the test time can be reduced to 1/k. In this paper, the failure rate test of VDMOS is carried out at 270 °C about 1500 hours with the accelerator factor k=21.73079. The storage lifetime of VDMOS was calculated over 10 years. The key parameters have been measured and reliability of VDMOS in ten years storage time has been evaluated.