Abstract: Provided is an accumulative sliding construction method of segmental track-changing for unequal-span structure, which divides the unequal-span structure into at least two sliding sections according to span variation, and a plurality of track segments corresponding to the spans of each sliding section. By providing sliders on the main truss/beam of each sliding section at positions corresponding to the track segments that each main truss/beam need to pass through, the sliding section smoothly passes through the sliding track segments to be in position; in addition, the main truss/beam of each sliding section is provided with temporary lengthening auxiliary structure or divided into an initial-mounted unit and rear-mounted units to allow the main truss/beam of each sliding section to pass through the track segments smoothly and to be in place.