Considering the health status assessment problem of lower accuracy and objectivity

the index uncertainty and importance degree was introduced

and then a method of health status assessment based on uncertainty and importance degree improved DSmT （DezertSmarandache theory） was proposed. Firstly

the uncertainty and importance degree was employed to determine the reasonable weight of index. Then the method of fuzzy comprehensive evaluation was used to determine the basic belief assignment of each index by building triangle trapezoidal membership function

and then the basic belief assignment was combined to get the assessment results using the weight DSmT fusion rule based on the index weight. Finally

the method was used to evaluate a power supply system. The results indicate that the proposed method can assign reasonable weight to the index

and the health status assessment result is consistent with the actual state.