Pressure recorder sub is composed of an upper joint, a cylinder body, a manometer joint and a lower joint. The pressure gauge is installed on the pressure gauge joint. When measuring the internal pressure, the two oil inlet holes on the upper joint need to be blocked with drain plug, and the drain plug on the pressure gauge joint can be removed. When measuring the external pressure, it is only necessary to remove the drain plug on the upper joint and plug the two oil inlet holes on the manometer joint with the drain plug.