The invention discloses a multi-unit communication test system realized based on FPGA. The multi-unit communication test system comprises a resource board, a PLC module and an upper computer. The resource board comprises an FPGA circuit, a drive circuit, an Ethernet module, an AC bus analog circuit, a DC power supply circuit, a clock circuit and a reset circuit. The PLC module comprises 20 clientside subunits PLC1-PLC20, and each client side subunit is provided with a work display lamp LED1-LED20, a switch S1-S20 and a server subunit PLC21. A client subunit, a work display lamp and a server subunit of the PLC module are connected with a drive circuit of the resource board; the drive circuit, the clock circuit and the reset circuit are connected with the FPGA circuit, and the FPGA circuitis connected with the Ethernet module. The system has the advantages that the number of serial ports is large, the communication speed is high, the test efficiency is high, and real-time programming control can be achieved through the upper computer, communication between the PLC units and communication between the upper computer and the PLC units are achieved on the basis of the FPGA chip, and the purpose of simulating the communication environment needed by a test to the maximum degree is achieved.