The invention provides a construction method of a cast-in-place concrete electric power cable pipe and belongs to the field electric power construction. The construction method comprises the followingsteps that a groove is excavated, specifically, the groove is mechanically excavated, the groove is a straight groove, and after mechanical excavation, artificial bottom clearing is conducted; waterdrainage arrangement is conducted, specifically, a vertical water drainage hole is excavated in the bottom of the groove, a water drainage pipe of a conical structure is arranged in the water drainagehole, and the smaller end of the water drainage pipe is downwards inserted in the water drainage hole, so that the water drainage pipe communicates with the interior of the groove; a concrete bottomplate is poured, specifically, the bottom of the groove is leveled, and the bottom plate is poured according to the design height and width; pipe laying is conducted, specifically, a dry sandy soil cushion layer is laid on the concrete bottom plate, and then the cable pipe is laid; and backfill is conducted. A cable pipe structure obtained through the construction method has the good water drainage effect and can conduct continuous water drainage during using, the interior of the groove is kept dry, thus, the cable pipe has the good working environment, the service life is long, the maintenance period is long, and the maintenance cost is reduced.