The invention provides an auxiliary device for laying tiles indoors, comprising: a base, a sliding structure, a lifting structure, a bracket, a bracket, a cement tank, an extrusion structure, a propulsion structure, a smearing structure and a connecting pipe. The upper surface of the base is provided with A sliding structure that can move laterally, the end of the sliding structure is fixedly installed with a lifting structure that can move up and down, the upper surface of the base is located on both sides of the bracket and the brackets are fixed symmetrically, and the brackets are located above the lifting structure Sliding superimposed ceramic tiles, the upper part of the tiles is provided with a cement tank that can hold the cement slurry, and the inside of the cement tank near the tiles is provided with an extrusion structure that can squeeze out the cement slurry, which reduces the labor intensity of the workers , effectively increases the working space of the workers, facilitates the laying work of the workers, effectively avoids the phenomenon that the tiles are broken due to accidents, saves the cost of decoration to a certain extent, and makes the grout spread more evenly on the back of the tiles .