Abstract: A kind of ultrasound power meter to measure high ultrasound power is developed. It is based on the radiation pressure method, mechanical balance and intelligent controlling techniques in the design. With different kinds of targets, include reflector or absorbing target, the output power of many kinds of ultrasound transducer can be measured by it. It is calibrated by weights and the error analysis shows that it has high resolution and high stability. With cone reflector and absorbing target, the power of a high intensity focused ultrasound treatment transducer driven at voltage in clinical application is measured by it. The results show that the ultrasound power meter can be used to measure high ultrasound power and it has high precision. Also the results show that the power output of high intensity focused ultrasound transducer has high stability when the driven voltage is from 600 V to 2200 V, which is usually applied by doctor. When the driven voltage is less than 600 V or higher than 2200 V, the output of the transducer will has error more than 5%.