Drainage pipe mounting and fixing structure and construction method thereof

The invention relates to the technical field of drainage pipe installation, and particularly discloses a drainage pipe installation fixing structure which comprises an upper fixing mechanism and a lower fixing mechanism, the upper fixing mechanism and the lower fixing mechanism are detachably connected, and the upper fixing mechanism comprises a lower supporting seat assembly. The upper end of the lower supporting seat assembly is in threaded connection with an upper pressing seat assembly, the two ends of the lower supporting seat assembly and the two ends of the upper pressing seat assembly in the length direction are connected with bending assemblies respectively, and fixing assemblies are symmetrically arranged on the left side and the right side of the lower supporting seat assembly and the left side and the right side of the upper pressing seat assembly. Two-point supporting is formed through the angle supporting assembly at the lower end of the connecting block and the height adjusting assembly, corres