The invention relates to a method for mounting of a pectination slideway well-shaped beam, and particularly relates to a linear control method for high precision mounting of a pectination slideway well-shaped beam based on a coordinate system. According to the method, a preassembly coordinate system is built during preassembly, horizontal alignment of a slide well-shaped beam steel rail is indicated by sprayed marks and then is converted into an underground mounting coordinate system, and underground mounting is adjusted according to the horizontal alignment and preassembly mounting inclination angle of the underground mounting coordinate system to achieve the purpose of controlling errors. The method has the advantages that the coordinate system is converted into the underground coordinate system through a mathematical model, and the points on the slideway well-shaped beam steel rail are in one-to-one correspondence, so that the entire mounting is in good order, the mounting errors are reduced and controlled within the range of +/-1mm, and the construction accuracy is greatly improved.