The invention discloses a travelling mechanism for a coach air conditioner shell molding die frame. The travelling mechanism comprises a base and a trolley; the trolley comprises a square trolley frame, pulleys and a driving device; the two sides of the trolley frame are each provided with a gear and a group of pulleys; each gear is installed on a driving shaft; the axes of the gears are parallelto that of the pulleys; the driving shaft is connected with the driving device; the base is respectively provided with rails corresponding to each group of pulleys; the trolley frame is supported on the rails through the pulleys; the two groups of rails are parallel to each other; the base is provided with gear racks corresponding to the gears; each gear rack is meshed with the corresponding gear;and the gear racks are arranged in a manner of being parallel to the rails. The travelling mechanism disclosed by the invention is simple in structure, realizes limitation on jitter of the trolley frame in the vertical direction, and guarantees the mold locking precision so that the product quality is guaranteed; the four corners of the trolley frame of the travelling mechanism disclosed by the invention are each provided with a guide wheel; and each guide wheel is arranged in a guide groove formed by the corresponding rail arranged below the corresponding pulley, so the running precision ofthe trolley is guaranteed, and the product quality is further guaranteed.