The invention discloses automatic inner formwork equipment suitable for pipe gallery construction and a construction method thereof. The automatic inner formwork equipment comprises an inner formwork,a moving trolley and a control system, and the control system controls walking of the moving trolley and telescoping reinforcement of telescopic I-beams of the inner formwork. The moving trolley of the equipment can carry the inner formwork to a specified construction site, and the action of placing and spreading the inner formwork can be automatically completed through an automatic loading and unloading mechanism of the moving trolley in cooperation with supporting jacks and the telescopic I-beams of the inner formwork. By adopting the control system for control, the problems that in the prior art, the labor intensity of workers is high, many potential safety hazards exist, the construction efficiency is low and the input cost is high are effectively relieved, and the function of automatic construction is achieved.