Abstract: A new type design technology of PCB which contains PTFE and FR4 has been investigated. This highly integratedtechnology realize the miniaturization and light of the system. The design of through hole is very important in high-speed hybridPCB, which may impact the signal integrity. EMI of the high-speed PCB which took by through hole is researched in this paper.when the signal transfers in the high-speed PCB After optimizing, it can achieve broad band、low insertion loss、low SWR.