The invention provides a hollow cement prefabricated slab forming mold. The hollow cement prefabricated slab forming mold comprises a base and a forming device, convex sliding grooves are formed in the right end of the base from front to back at equal intervals, and the forming device is arranged at the upper end of the base. According to the hollow cement prefabricated slab forming mold, the problems that firstly, when traditional hollow cement prefabricated slabs are formed and processed, a pouring frame is usually placed on the ground, and then concrete is poured into the pouring frame through workers, so that vibration treatment cannot be carried out on the concrete, the concrete cannot be evenly mixed, bubbles are prone to being left in the concrete, then defects of hollow cement prefabricated slabs are caused, and therefore the later use quality of the hollow cement prefabricated slabs is influenced; and secondly, a few manufacturers adopt prefabricated slab forming machines when the hollow cement precast slabs are manufactured, and the machines cannot adjust the distance between pore channels of the hollow cement prefabricated slabs according to processing requirements, and therefore the applicability is low, and forming and processing can not be carried out on the hollow cement prefabricated slabs with different specifications are solved.