Abstract: As one of the common facilities for laying cables, cable ducts are usually made of materials such as reinforced concrete or glass fiber reinforced plastic, and have multiple functions including rainproofing, fireproofing, explosion protection and facilitating personnel maintenance. The construction of cable ducts in hydropower plants is often the renovation, upgrading or reconstruction of existing facilities, which is susceptible to restrictions such as uneven terrain, steep slopes, cross-operation and facility protection,thus imposing high requirements on the safe and civilized production of the project. Focusing on the construction of cable ducts on high and steep slopes, this paper discusses the construction difficulties and corresponding solutions by taking the cable duct renovation project from the No.2 powerhouse to the dam surface of Huanglongtan Hydropower Station as a case study, which can provide reference for other similar projects.