The square tube polishing machine is one type of polishing and grinding equipment, suitable for rust removal and mirror polishing on the outer surfaces of various rectangular cross-section metal profiles. The polishing process is dry, allowing for different levels of coarse and fine polishing in each session. This machine can be used for sanding and polishing on square surfaces of aluminum, iron, copper, and stainless steel (by modifying the shape of the polishing wheel, it can also polish profiles with non-standard cross-sections).