The invention relates to an erection oil tank and belongs to the technical field of erection systems. The problem that in the prior art, an erection oil tank cannot release high-pressure high-flow oilliquid in a short time and the erection speed cannot be lifted is solved. The erection oil tank includes a gas generator and an oil tank. A piston is arranged in the oil tank. The piston divides an internal space of the oil tank into a propulsion chamber and an oil storage chamber containing liquid oil. A gas outlet of the gas generator is communicated with the propulsion chamber. When the erection oil tank is used, the oil storage chamber is communicated with a liquid inlet of the erection oil tank of an erection system. The erection oil tank can be used for supplying oil for an erection oilcylinder of the erection system.