The invention provides a notching device for construction of inner wall faces of the building. The notching device comprises a bottom plate, a working table and a notching machine installing plate. Asliding way is arranged on the upper surface of the bottom plate. A rotating drive mechanism and a rotating locking mechanism are arranged on the upper portion of one end of the bottom plate. The working table is arranged above the bottom plate. A through sliding groove is formed in the length direction of the side face of the working table. The notching machine installing plate is arranged abovethe working table in a sliding manner, and a notching machine is installed on the notching machine installing plate. The working table is supported by means of a main supporting mechanism and an auxiliary supporting mechanism, and adjustment in the height direction and the change of the using state can be carried out. According to the notching device, the arranged working table can provide an operating track and support for the notching machine, the position of the working table in the height direction can be adjusted, the change between the traverse state and the vertical state can be carriedout, and the requirements of transverse notching and vertical notching can be met.