The invention relates to an auxiliary device for controlling stone panel gaps and belongs to the field of building construction. The auxiliary device comprises a cross gap beautifier which is made from PA66 polyamide nylon material and used for controlling the tone panel cross gap, and a horizontal gap beautifier used for controlling the stone panel linear gap. The cross gap beautifier is composed of a cross panel, two horizontal detector plates and two vertical detection plates, and the two horizontal detector plates and the two vertical detection plates vertically extend along the lower surface of the cross panel. The horizontal gap beautifier is composed of a rectangular panel and two horizontal detector plates perpendicular to the lower surface of the rectangular panel. The auxiliary device is simple in structure, convenient to use, high in practicability and capable of controlling the size of the gaps formed by stone panels.