With the rapid development of electronic information technology and industrial automation, the application of measurement technology in product automatic detection is becoming increasingly widespread. In response to the limitations of traditional frequency response methods, this design proposes a line load and fault detection device based on FPGA + DSP architecture. Through amplitude frequency characteristic analysis, the measurement of a single RCL component and the identification of the load structure network are achieved. The system adopts TI’s DSP chip and Altera’s FPGA as the core controller, and uses SCI protocol and SPI protocol to control the digital to analog converter and data display. Actual testing has shown that the device can accurately identify load open circuit and short circuit faults, and can identify 8 types of RLC component structural networks. The measurement error is small, the measurement time is short, and the performance meets the expected indicators. The success of this design provides new ideas for product detection devices and has broad application prospects.