The invention provides an automatic boost-type setting load guaranteeing device, pertaining to the field of hydraulic equipment; the setting load guaranteeing device consists of a cylinder body internally provided with a piston which dividing the cylinder body into an upper cavity and a lower cavity; the cross-sectional area of the upper cavity is smaller than that of the lower cavity; the upper end of the cylinder body is provided with a lid body, and the lower end of the cylinder body is provided with a base; a passageway communicated with a pump station, a passageway communicated with the upper cavity, a pressure releasing passageway and a liquid draining passageway are arranged in the lid body; and the upper cavity and the lower cavity are communicated by an elbow pipe. The invention solves the problem that a hydraulic support upright post or a single hydraulic support can not have sufficient setting load due to the insufficient pressure of the pump stations, pipeline loss and leakage or the reason that operators place an operating valve to a neutral position too early, without affecting other movements of the hydraulic support. The setting load guaranteeing device has simple structure, reliable performance and convenient installation and application.