Plate rolling machine capable of being automatically adjusted and machining method of plate rolling machine

The plate rolling machine comprises a plate rolling machine body, a heating spray gun mechanism is arranged above a treatment bin in a plate pretreatment mechanism of the plate rolling machine body, and protective doors are arranged at inlets and outlets in the two sides of the treatment bin correspondingly; hydraulic oil cylinders are symmetrically arranged above the positions, close to the two ends, of the protective door, a positioning machine table is arranged on one side of the plate pretreatment mechanism, a conveying roller is arranged in a feeding roller mounting groove in the center of the interior of the positioning machine table, clamping supports are symmetrically arranged in the positioning machine table, and the hydraulic oil cylinders are arranged on one sides of the clamping supports; a rolling mechanism and a cooling mechanism are arranged above the portion, on one side of the positioning machine table, of the machining machine table, a cooling liquid recycling groove is formed below the righ