Firstly, the performance degradation failure mechanism of electric spindle was analyzed and researched. Under this premise, the suitable performance degradation characteristic quantities were selected. On this condition, the reliability testing scheme of electric spindle was designed. The reliability testing of electric spindle was done under the guidance of the scheme. Then, the basic principle of reliability evaluation method of degradation data which was based on distribution of false life was studied. In this basis, the method combined with the reliability testing data of the electric spindle’s testing sample and integrated virtual augmented sample method was applied to assess the reliability of electric spindle. Eventually, failure distribution function, distribution density function and its curve were got. A series of reliability indices were achieved, including reliability function and its curve, failure rate function and its curve, average life, part of reliable lives and so on.