Prefabricated stair for fabricated building

The utility model discloses a prefabricated staircase for an assembly type building, which belongs to the technical field of prefabricated staircases and comprises two mounting tables and a staircase body mounted between the two mounting tables, mounting grooves are formed in the side walls of the sides, close to the staircase body, of the two mounting tables, and mounting blocks are fixedly connected to the two ends of the staircase body. The installation block is arranged in the installation groove, the peripheral side wall of the installation block is attached to the inner side wall of the installation groove, a protruding block is fixedly arranged on the inner bottom wall of the installation groove, a groove is formed in the bottom end face of the installation block, the protruding block is clamped in the groove, and the peripheral side wall of the protruding block is attached to the inner side wall of the groove. By means of the arrangement, compared with the prior art, the assembly process of the stair