The invention relates to the field of casting cleaning, in particular to a gray pig iron pipe mechanical cleaning and dust removing device. The device includes a horizontally-arranged support mountingplate, a lifting mounting plate is horizontally arranged over the support mounting plate, hydraulic lifting columns are vertically arranged at the four corners of the support mounting plate, the upper ends of the hydraulic lifting columns are connected to the lifting mounting plate, the middle position of the lifting mounting plate is longitudinally provided with a limited guide groove, a mobileinstallation plate is arranged longitudinally in cooperation with the limited guide groove, and steering mounting columns are symmetrically arranged on the portions, opposite to the support mounting plate, of the limited guide groove. Through gear and rack engaged transmission and hydraulic lifting cooperated adjustment, the working height of the device can be stably and accurately adjusted, and operation is ensured; through rotary clamping and fixing, gray pig iron is simply installed, and debris can be stably exported in the cleaning process; through limited guide movement and deflection, the device can perform multi-position cleaning operation, and the cleaning quality and efficiency are improved.