The present invention discloses a transversal bilateral diffusion MOS transistor with high pressure resistant, which belongs to micro-electronics semi-conductor device field. The device includes a gate region, a source area, a drain region, a tagma, a gate medium and a drift region, the setting drift region is placed between the tagma and the drain region, and the doping type is opposite to the tagma, an insulating medium region and a doping region which is opposite to the doping type of the drift region are equipped in the drift region, and the doping concentration of the doping region is higher than that of the drift region, the doping region is adjacent to the tagma, however the insulating medium region is adjacent to the drain region. Because the insulating medium region and the doping region are inducted into the drift region at the same time, the effective depth of the drift region is reduced effectively to make the electric field more uniform and increase the equivalent length of the drift region, the resistant high Voltage characteristic of the transversal bilateral diffusion MOS transistor device of the present invention is good.