Abstract: Nowadays, the competition in the field of domestic semiconductors largely depends on the competition of semiconductor equipment and core components. The anti-interference ability and stability of the equipment are important criteria for judging the quality of equipment. For the RF power equipment, the accuracy, stability and fast response of the control loop are important indicators that determine the performance of this product. Therefore, this paper designs a pure hardware circuit power signal detection loop based on the related principles of capacitor voltage sampling, current transformer sampling and op-amp circuit, and uses the simulation software Multisim to perform simulation experiments, and the output voltage is numerically equal to experimental results of output power. At the same time, by changing the input power of the bus signal, it is obtained that the output voltage and the input power have a very high linear correlation, so the detection loop has good stability and can be applied to the detection of radio frequency power in a large range.