The invention discloses a shield tunnel bottom backfill fabricated construction method. The backfill fabricated construction method comprises the following steps that firstly, during the constructionof a shield tunnel, precast blocks and shield pipe pieces are fabricated simultaneously, and the blocks are connected by bolts; then, grouting materials are injected into the space between the lower surfaces of the precast blocks and the inner surfaces of the pipe pieces through grouting holes reserved on the precast blocks; in addition, cast-in-place of a leveling layer of a construction track base plate and differential-settlement longitudinal beams arranged on corresponding areas of both sides of the precast blocks is carried out on the upper surfaces of the precast blocks. By engineering practice verification, according to the shield tunnel bottom backfill fabricated construction method, tunnel backfill and the shield tunnel can be constructed synchronously, the construction efficiencyof tunnel backfill is enhanced, the overall construction period of the shield tunnel is shortened, the operation environment of tunnel bottom backfill is improved, and the construction safety risk isreduced.