Abstract: In order to improve the communication stability and instruction execution speed of PLC-programmable controller,use a PLC host structure with ARM for control module and FPGA for parallel processing module.On the one hand,ARM control module needs to communicate with hand programmer and human-computer interface through the CAN bus.They form a control LAN and realize point-to-point communication.In this way,the system can enhance information transmission stability and validity.On the other hand,facing the new instruction system this paper has designed a method of program compiling according to the characteristics of the parallel arithmetic FPGA.The method of program compiling has two processes with static and dynamic compiler.They organize PLC instruction into a list data structure and recompile them into new user instruction sequences which are suitable for FPGA parallel operation and then send to FPGA to process through the interface of message exchanging between ARM and FPGA according to the communication standard.By testing,verify the effectiveness of the method.