The invention provides a composite building template compound system. The composite building template compound system comprises a stair template and a closed type internal corner template. The stair template comprises blocking plates, pinking teeth, stair side plates, stair treads and stair risers. The stair treads and the stair risers are arranged sequentially from bottom to top in a staggered mode to form steps. The steps are installed between the stair side plates and the inner side faces of the pinking teeth. The outer side faces of the pinking teeth are arranged on a wall. The blocking plates are arranged at the bottoms of the pinking teeth, the stair side plates and the steps. A closed-opening type pouring space is formed among the blocking plates, the pinking teeth, the stair side plates, the stair treads and the stair risers. The upper end faces of the stair treads are provided with feed inlets. The closed type internal corner template comprises first end plates and first side plates which are connected mutually to form a cuboid. Any two adjacent first side plates are provided with a connection part and an operation part. The operation parts are connected in a butt joint mode in the intersections of the first side plates. The connection parts are provided with first connection holes. The operation parts are provided with operation holes. The composite building template compound system is a complete set of system.