Abstract: In order to avoid the disadvantages of the traditional Optical Power Meter Method, such as the large measuring error and the narrow measuring range,this paper is deigned to explore the measurement accuracy of the Optical Power Meter and the optimization of the measuring range. In this design, photodiode PIN is used to convert light current into voltage values. And the employment of the logarithmic amplifier AD8304 can avert the sophisticated logarithm operation and the error by using the linear amplifier. The design thought of the Optical Power Meter is provided in this paper, which focuses on the special characteristics of the logarithmic amplifier AD8304 and the application of the Optical Power Meter. And the calculation accuracy of this design has been verified by software.