The invention relates to a polishing device, in particular to a uniform side and corner polishing device for mosaic tiles. The technical aim of the uniform side and corner polishing device for the mosaic tiles is to enable side and corner polishing to be uniform. In order to achieve the above technical aim, the uniform side and corner polishing device for the mosaic tiles is provided and comprises a base plate, a right support, an electric wheel, a fixing plate, a first pull wire, a first fixed pulley, a second fixed pulley, a first swing base, a left support, a wedge block, a contact idler wheel, a lifting rod, a second swing base, a second pull wire, a fixing block, a third spring, a first spring, a second linear actuator, a rotation motor, a pressing plate, a containing plate and the like. The left end and the right end of the top of the base plate are provided with the left support and the right support correspondingly. By means of the uniform side and corner polishing device, the effect of being uniform in side and corner polishing is achieved; when the uniform side and corner polishing device is used for side and corner polishing of the mosaic tiles, the polishing angle can be adjusted, and polishing can be more comprehensive; and meanwhile, the manpower for polishing is saved.