The invention relates to a construction method for mounting an outdoor embedded high-density polyethylene double-wall corrugated drain pipe (CPP).The method is characterized by comprising the following processes of foundation trench digging, pipe mounting and backfilling, wherein the foundation trench digging technical process comprises measuring and setting out, mechanical grooving, levelling and tamping of a groove bottom, grit gravel cushioning and foundation sanding; the pipe mounting technical process comprises pipe mounting, well chamber building and rendering; and the backfilling technical process comprises soil filling for a chest, a water tight test, soil backfilling and tamping. The method solves the problems of discharge of rainwater and sewage of current municipal engineering, industrial wastewater discharge, subdistrict drain engineering, low speed for cement and metal pipe construction in the engineering of pipelines preburying and the like, heavy pipe weight, inconvenience for conveying and carrying, large labor intensity, high mounting cost and the like, and is applicable to the discharge of the rainwater and the sewage of the current municipal engineering, the industrial wastewater discharge, the subdistrict drain engineering, and the construction for mounting engineering drain pipes such as the pipelines preburying and the like.