The invention relates to a high-level oil tank low-level fuel charging system and aims at solving the problem that a high-level oil tank needs high-level fuel charging and accordingly causes safety risk and providing a high-level oil tank low-level fuel charging system. The high-level oil tank low-level fuel charging system comprises an oil tank and is characterized by further comprising an oil pump, a motor driving the oil pump to rotate, a control circuit controlling the motor to rotate and a fuel charging pipe, wherein one end of the fuel charging pipe is connected with the oil tank, the other end of the fuel charging pipe is connected with an oil outlet of the oil pump, an oil suction pipe is connected to an oil inlet of the oil pump, a branch pipe is arranged on the fuel charging pipe, and a rapid connecting connector is arranged at the tail end of the branch pipe. The high-level oil tank low-level fuel charging system has the advantages of being simple in operation, automatic, convenient, fast, safe, reliable and the like, and more convenient and more effective service guarantee is provided for usage of engineering equipment.