The invention discloses a method for falling of a steel trough beam in bridge walking type pushing construction, and relates to the technical field of bridge construction. The method comprises the following steps that walking type pushing equipment is arranged at the top of a cover beam; two pier-side brackets are arranged on the two sides of the cover beam respectively, and are oppositely arranged; after the steel trough beam is pushed to a preset beam falling position, the walking type pushing equipment is started to jack the steel trough beam up, then two steel cushion blocks are arranged on the top faces of the two pier-side brackets respectively, and the steel trough beam is made to fall on the two steel cushion blocks; the walking type pushing equipment is removed, padstone is arranged at the top of the cover beam, and a support is fixedly arranged at the top of the padstone; two vertical jacking jacks are arranged at the tops of the positions, on the two sides of the padstone, of the cover plate respectively and controlled to jack up the steel trough beam, then the steel cushion blocks are removed, the two vertical jacking jacks fall back synchronously, and the steel trough beam falls on the support; and the steel trough beam and the support are fixedly connected, the vertical jacking jacks are removed, the pier-side brackets are demounted, and falling of the beam is completed.