The invention relates to a horizontal directional drilling machine pull strength instant lifting control system. The horizontal directional drilling machine pull strength instant lifting control system comprises a hydraulic pump, a hydraulic motor, solenoid valves, a first overflow valve and a multitandem valve, a second overflow valve is integrated to the multitandem valve, the hydraulic pump iscommunicated with an oil port of the hydraulic motor through an oil port of the multitandem valve, the hydraulic pump is communicated with the second overflow valve and an oil tank through the solenoid valve, and the hydraulic pump is communicated with the first overflow through the solenoid valve and then is communicated with the oil tank. According to the horizontal directional drilling machinepull strength instant lifting control system and the control method, the pressure setting value of the second overflow valve is lather than the pressure setting value of the first overflow valve, electromagnets on the solenoid valves are controlled to be powered on or powered off to further control communication or non-communication of an oil outlet of the hydraulic pump and an oil inlet of the first overflow valve, the maximum working pressure pulling of a hydraulic system is lifted, the requirement for instantly lifting pull strength of the horizontal directional drilling machine is met, lifting is accurate and quick, the structure is simple, cost is low, the construction safe is guaranteed, and the machine performance is sufficiently achieved.