This paper introduces the PLC highspeed counting module based on FPGA design. The core counting part of the module is finished by FPGA, and then the CPU reads the counting result throughinterface of the SPI. The response delay will only be affected by the FPGA internal clock delay and external configuration circuit. The highspeed counting module can implement frequency counting, pulse counting, coding count and other different scenarios of the counting function and achieve high accuracy of high frequency pulse count and improve the realtime responsiveness.In addition the module has 8 differential digital outputports which can be controlled by the count results.