The invention discloses a construction method and device for tunnel arching accurate positioning and fixing. The method comprises the following steps that the center line of a tunnel is measured, and according to the position of the center line, an arching operation trolley and a laser distance measuring instrument are distributed; through the laser distance measuring instrument, the preset arching position and surrounding rock key points are determined, and the surrounding rock key points comprise the set positions located at the arch foot and the arch top, and drill holes are stricken in the key points; an arching is mounted to the arching position, steel plates with via holes are arranged on the arching, and the via holes correspond to the drill holes; and an anchorage material is mounted in the drill holes, and threaded steel bars are inserted into the drill holes through the via holes to enable the anchorage material to anchor the threaded steel bars.