Integrated drainage pipe, drainage system and construction method of drainage system

The invention provides an integrated drainage pipe, a drainage system and a construction method of the drainage system, and relates to the technical field of drainage systems. The integrated drainage pipe comprises a first sleeve and a second sleeve, first water seepage holes are formed in the peripheral wall of the first sleeve, second water seepage holes are formed in the peripheral wall of the second sleeve, and the second sleeve is arranged in the first sleeve in a sleeved mode; a first gap is formed between the second casing pipe and the first casing pipe, the first gap is filled with a first filtering medium, the first filtering medium is arranged between the first casing pipe and the second casing pipe, reverse filtering of silt can be achieved, the drainage pipe is prevented from being blocked by the silt in the drainage process, and the problems that the drainage pipe is blocked, drainage is not smooth and the like are solved; efficient drainage is achieved, the permeability of the interior of soil a