Different solutions of maintenance and operation should be taken for equipment at different health levels.The current testing and evaluation of equipment is still realized by the “true or false” method,which can only describe whether the equipment is normal or not,and the health level can't be evaluated.Aiming at this problem,a health status assessment method based on improved evidence theory is proposed,taking a certain type of servo mechanism as the research object.Firstly,a set of parameters is proposed to represent the health of the servo mechanism comprehensively,and a normalization method is used to process the test data.Furthermore,the membership of each processed parameter is fused based on the improved evidence theory,and thus the health status level of the servo mechanism is obtained.Finally,the proposed method is verified by the case study to a certain servo mechanism.It is demonstrated that the proposed method is valid,with certain application value.