Abstract: Beam loss may lead to significant radiation damage to accelerator equipment. To prevent damage to machine materials and allow for manual maintenance, a beam loss monitoring system for the HIAF project has been designed. The system receives signals from a fast response beam loss detector based on plastic scintillators, and uses pulse counting and ADC integration of two data channels to determine beam loss. Implement the integration algorithm for each time window using Xilinx Kintex-7 series FPGA, and provide triggering interlock protection signals for each window. The detector data acquisition module adopts a 16 bit high-precision ADC with a sampling frequency of 20 MSPS, which can achieve continuous sampling of detector data for subsequent data processing and interlock judgment. Through laboratory testing, the beam loss monitoring system accurately detected the occurrence of beam loss and promptly provided interlocking protection signals, providing data support for the normal operation of the accelerator.