In this paper,an improved threshold selection method is proposed to solve the problem that the same frequency multi-cell detection,which is affected by noise and interference in5G field testing.The detection threshold is determined by block calculation of signal-to-noise ratio and peak-to-average ratio,and the channel estimation algorithm based on DFT can further reduce the influence of noise on signal detection.After the first strong cell is detected,it is set as interference signal.Using signal reconstruction and interference elimination algorithm,the detection probability of effective 5G cell can be further improved.In hardware implementation,the multi-core parallel signal processing capability of DSP is fully utilized to further improve the efficiency of block detection.Simulation experiments compare the detection results of the proposed algorithm and the traditional algorithm under different scenarios,and the platform measurement verifies the effectiveness and reliability of the proposed algorithm.