Alternating current filed measurement (ACFM) is an electromagnetic non-destructive testing technique for detecting defects on metal surfaces and near surfaces. ACFM data acquisition system uses the programmable logic device FPGA and A/D converter to quantize and control the signals according to the selection of the work piece to be inspected, and then realizes the data communication between the PC and the hardware through the serial communication mode to complete the acquisition and digitization of the signal. In this paper, the upper computer software was developed based on the Java+MySQL database platform, and the serial port communication Serial Tool relying on development was used to complete the data transmission. The My SQL database was used to extract the target data from data packets, which completed the data storage and analysis, then realized the defect identification and sized quantization inversion function. What’s more, Jfrerchart was used to complete the two-dimensional graph drawing of the target data. The software improves the efficiency of data acquisition and processing, and the research results are of great significance for the detection and evaluation of surface defects.