To reduce the frequency of replacement of a cutting edge due to abrasion caused by trimming in a cutting edge fitting device for fastening a cutting edge to a blade by a bolt in a construction machine.

A blade main body 4 is provided with a screw hole 4a where a screw part of a bolt 6 is screwed, and a cutting edge 7 is provided with an oblong hole 7a in which the buckling direction of the cutting edge 7 and the longitudinal direction coincide with each other. The cutting edge 7 is fastened on the blade main body 4 by the bolt 6 positioned at the left end of the oblong hole 7a. With trimming, the cutting edge 7 wears away, and if the amount of buckling from the blade main body 4 is decreased, the bolt 6 is loosened to move the cutting edge 7 in the direction of an arrow L, thereby adjusting the buckling amount.