Provided are a prefabricated integrated pipe gallery transport overturning vehicle and a construction method thereof. The prefabricated integrated pipe gallery transport overturning vehicle includes atransport vehicle, rotation supporting legs and an L-shaped overturning bracket. The L-shaped overturning bracket is disposed on the transport vehicle and can be overturned relative to one side of the transport vehicle, the number of the rotation supporting legs is at least one, and the rotation supporting legs are disposed on the transport vehicle side where the rotation supporting legs are overturned relative to the transport vehicle to effectively improve the stability of the vehicle during the overturning of the L-shaped overturning bracket. Therefore, the prefabricated integrated pipe gallery transport overturning vehicle is simple in structure and convenient to operate. Against the shortcomings of functions of an existing pipe gallery transport vehicle, pipe gallery horizontal transport can be achieved, and the problems on stability and line transport limit during the transport are solved; after the transport is in place, a prefabricated pipe gallery pipe joint is overturned ina sunken mode, so that the safety during the overturning is ensured, the overturning height is also reduced, and the risk of collision with a supporting cross arm on the upper portion of a foundationpit is avoided.