Reinforcing and seepage-proofing treatment method for ultra-shallow covering soil of construction riverbed of tunnel undercrossing riverway

The invention discloses a reinforcing and seepage-proofing treatment method for ultra-shallow covering soil of a construction riverbed of a tunnel undercrossing riverway. The reinforcing and seepage-proofing treatment method comprises the following steps of (100) desilting a riverway area which needs to be constructed so as to form a desilting area with gradient on the periphery and lower than the riverbed, and burying a top pipe stretching across the riverway in the lower layer of the desilting area; and (200) sequentially laying a waterproof layer and a covering layer on the desilting area by using a device, and forming a film bag concrete covering layer attached to the waterproof layer below after concrete is injected into film bag concrete of the covering layer and solidified. According to the reinforcing and seepage-proofing treatment method, a steel cable track stretching across the riverway is formed, a sliding base sliding along the steel cable track is arranged on the steel cable track and is used fo