With the development of microelectronics processing technology, integrated circuits are increasingly sensitive to static electricity. A reasonable and effective design of ESD protection devices seems increasingly important. It is time consuming and labor intensive for the traditional design method which is “manual calculation and tapeout verification”. Based on GGNMOS devices, Sentaurus simulation platform is uesd to establish the device model in this paper.Considered the needs of ESD protection capability, we calculate the design parameters of GGNMOS,design a tube which protect capacity can reach 4.5 kV for the HBM.The results show that the method is simple and effective,can greatly shorten the design cycle,which can regarded as an excellent method for protection device.