Step joint type self-staggered joint internal corner template

The invention discloses a step joint type self-staggered joint internal corner template, belongs to a building template, and aims to overcome the defects of slag inclusion and necking caused by high probability of mud leakage at a joint of an existing press board. A right-angle complete plate including two right-angle edges is integrally formed by plastic; a joint of a step is arranged on the inner sides of the two right-angle edges respectively; the joint of the step indicates a step form which is formed by a staggered joint lapping edge arranged within the thickness range of the right-angle edges and a staggered joint step higher than the staggered gap lapping edge; the staggered gap steps on the two right-angle edges are connected to be right-angled and are positioned on the inner sides of the included angle of the right-angle complete plate; the thickness of the staggered joint lapping edge and the height of the staggered joint step are 1/2 the plate thickness of the right-angle edges respectively; the thickness of the right-angle edges is equal to the plate thickness of the template. During formwork support, the internal corner template is placed at an internal corner of to-be-cast concrete and is lapped and coupled with the template on the plane of the to-be-cast concrete through the joint structure, the formwork supporting efficiency is high, mud leakage does not occur at the corner of the cast concrete, and the defects of slag inclusion and necking are avoided.