Based on the phased array chip amplitude and phase calibration system, a self-calibration algorithm is proposed to improve beamforming quality. After calculating the error of each state, only by traversing the errors of all phased array chip states once, the target state could be screened out and a Look-Up-Table (LUT) could be generated. During screening, the amplitude error and phase error of a single target state and the RMS error of all target states calculated by Coordinate Rotation Digital Computer (CORDIC) were constrained. Then, the phased array chip could achieve 6-bit phase shift (360°) with error (RMS) less than 2° and 6-bit attenuation (32 dB) with error (RMS) less than 0.3 dB. Compared with the exhaustive search and successive approximation methods, the calibration scheme saves LUT generation time. According to the algorithm, a self-calibration chip is designed in a 65 nm CMOS technology with die area of 584 613.16 μm2.