The design of the electronic system mostly enters the area of nano-sized high-sized high-speed. The clock frequency becomes higher and higher, which makes even a very short wire becoming the transmitting antenna possible. Then the wire radiates to the space as to form the electromagnetic interference(EMI). Along with the constantly improving of electronic system property, the problem of electromagnetic property of PCB will be the key to the success of high-speed circuit system design. In order to conquer the problem of electromagnetic interference(EMI) and explore rational way of high-speed PCB design, the paper, using the field theory as the analysis method, together with the electromagnetic simulation software Designer and HFSS and SI-wave, it carried on the theoretical research and the simulation analysis of the essence and condition of the cause of EMI in high-speed PCB and the method of restraining interference. It selected the minimum control system of PCB built by TMS320VC5416 chip of IT Company as the research object, conducted researches on the electromagnetic property. In the end, using the actual high-speed circuit, a minimum control system of PCB built by TMS320VC5416 chip, the paper did field simulation analysis and got the current distribution pattern and the EM near-far field distribution pattern. Based on the analysis, PCB design is optimized to obtain products with better electromagnetic property. It provide a fantastic approach to the high-speed PCB design