In the case of equipments’ performance degradation which partially results from measuring, the model which is only based on the degradation data itself cannot reflect the true degradation process, and it is unable to forecast and evaluate effectively, especially when the degradation quantity caused by measures cannot be ignored. In order to solve this problem, firstly, the equipment's degradation process model which contains the damaging quantity induced by measuring was established on the basis of Wiener process; then the method of parameters estimation and real-time updating method for equipment's residual life based on Bayesian theory were presented. Finally, a simulation example was presented to testify the significance of this research and the validity of models.