To provide a construction method of filling with fillers for joint-gap sealing, by which a construction can be performed by inserting equipment into joint gaps from a side on one end side in a direction orthogonal to a bridge axis of joint gaps of a road bridge or the like.

The construction method of filling with fillers for joint-gap sealing includes: a first step of preliminarily preparing a first pipe body 15, including a plurality of discharge holes 15c, and a plurality of second pipe bodies 16 which can be connected by being successively threaded; a second step of forming a joint-gap cutoff foam 13 by injecting foaming material into the first pipe body 15 while horizontally inserting the first pipe body 15 into a joint gaps 10; a third step of forming the joint-gap cutoff foam 13 by pushing the second pipe bodies 16 while threading the second pipe bodies 16 to the first pipe body 15 and injecting the foaming material inside; a fourth step of continuously forming the joint-gap cutoff foam 13 over a full length of the joint gaps 10 by repeating, multiple times, threaded connecting and pressing of other second pipe bodies 16 to the second pipe bodies 16, the injection of the foaming material to the inside and the formation of the joint gap cutoff foam 13; and a fifth step of sealing the joint gaps 10 in a watertight state by filling an upper space of the joint-gap cutoff foam 13 with fillers.