The utility model relates to a cable pit laid on the power transmission sequence framework, especially a power transmission sequence L type assembled cable pit, its structural feature lie in, the cable pit saves ditch body head and the tail by the plural number and connects to form according to the preface, and every section ditch is personally experienced sth. Part of the body including the prefabricated component of two L types, and this two L type prefabricated component splices into the U type ditch body in opposite directions, and it has a plurality of splice bolt hole to follow verticalevenly distributed on every L type prefabricated component's the bottom diaphragm, and two L type prefabricated component are in opposite directions to the carried forward, through horizontal bolted connection to the splice bolt hole realization fixed connection who corresponds, the preceding terminal surface of every section ditch body is provided with the tenon, and the rear end face then be themortise, the mortise joggle of tenon and preceding a lesson ditch body rear end face, the mortise then with back a lesson ditch body before the tenon joggle of terminal surface, form end to end's structure, the gap middling pressure that the joggle was located is equipped with the water -swelling rubber strip. The advantage lies in: the construction work volume shortens construction period, improves the efficiency of long -distance transport, the construction cost is reduced, the scope that the assembled cable pit was used has been enlarged in power transmission transmission line engineering.