Aimed at the requirement of reliability life assessment for high reliability and long life seals under small sample test,a reliability assessment method based on virtual augmented samples and Bootstrap method was proposed.Taking the step seal as an example,the life reliability evaluation was carried out.Firstly,the virtual augmentation method was used to increase the number of the step seal’s bench life test data to 10,in order to meet the applicable conditions of Bootstrap method.Then the life reliability evaluation result of the step seal was obtained by the Bootstrap method