For the current wireless radio communications system, the calibration effect of power amplifier(PA) is a good evaluation criterion for radio frequency(RF) power calibration to calibrate the power amplifiers. This paper analyzes the RF module and the control mechanism firstly, and a mathematical model constructed to transform the traditional problem of power calibration into parameters estimation. A least mean square(LMS) algorithm based on energy conservation is then proposed to regulate the accuracy and complexity. The method of calculating the algebraic variables limited to a certain range, and does not require strictly the distribution of the input data, which is quite excellent for PA calibration. The simulation results illustrate the proposed algorithm can suppress efficiently the output power within 0.5 dB.