Hydrocarbon of overpressure basins can vertically migrate along faults through inrush current when active fault cut through the overpressure source rocks.This process provides an important hydrocarbon source for largescale migration and accumulation. However, the research on the distance of hydrocarbon vertical migration is still in qualitative analysis stage, with less attention on pressure relief during fault opening and migration distance difference between hydrocarbon and the formation water. This paper shows that the height of hydrocarbon vertical migration along fault relies on the overpressure amplitude in source rocks. The larger the amplitude is, the farther the hydrocarbon can migrate vertically. Consequently, the top interface of upwelling is buried more shallowly.The initial position of hydrocarbon upwelling is not ground surface but the top of effective source rock. With vertical inrushing of a large volume of hydrocarbon, the pressure in overpressure belt releases rapidly so that great majority of hydrocarbon cannot reach the theoretical top interface of upwelling. Besides, taking the resistance of vertical migration along faults into account, the real height of vertical migration of hydrocarbon will be far lower than the theoretical migration distance.