Underpass road structure and construction method thereof

The invention discloses an underpass road structure and a construction method thereof, and belongs to the field of underpass roads, the underpass road structure comprises rainwater drainage systems, the rainwater drainage systems are arranged on longitudinal slopes on two sides of a bridge, and the rainwater drainage systems are used for collecting and conveying runoff rainwater. The underground water drainage system is arranged below the longitudinal slopes on the two sides of the bridge, the underground water drainage system is communicated with the rainwater drainage system, the elevation of the underground water drainage system is lower than that of the rainwater drainage system, the underground water drainage system comprises a plurality of blind pipes, a plurality of water passing holes are formed in the blind pipes, and the blind pipes are used for lowering the water level of underground water. Underground water is prevented from seeping to a longitudinal slope coverage area through the waterproof reta