The purpose of the paper is to research a new method of detecting and evaluating balance function of old people for improving the quality of balance evaluation. The methods of evaluating balance function include as follows. Firstly, intuitional methods include observatory and questionnaire. Secondly, the Center of Pressure (CoP) andCenter of gravity (CoG) of an old people are detected to evaluate static and dynamic balance function with scientific equipment. The dedicated micro-machining accelerometer and angular rate sensors are effective in detecting the center of gravity (CoG). Finally, different algorithms were applied respectively to evaluation of static and dynamic balance function.