Underwater power cable laying is mainly used for the interconnection between land contact networks and oil production platforms, and is mainly used for the transmission of high-energy electricity on the seabed. The complex technologies used in submarine cable engineering include environmental detection, marine physical exploration, cable design, manufacturing, and installation. The article introduces the construction and testing methods of submarine cable laying. Underwater cable laying mainly includes three stages: line survey and cleaning, submarine cable laying, and erosion protection. When installing cables, it is necessary to control the sailing speed of the laying vessel, cable release speed, cable entry angle, and laying tension to avoid damage to the cables due to small bending radius or excessive tension. Use underwater monitors to control the forward speed, direction, and cable laying speed of the laying ship. The next step of construction is mainly to provide deep burial protection for submarine cables, in order to reduce the impact of complex marine environments on submarine cables and improve operational safety. Use high-pressure flushing method to discharge a 1.5 meter deep ditch, bury steel cables in it, and backfill naturally to form protection. Submarine cable construction method cable route survey and cleaning design provides technical information related to submarine route review, understanding the following seabed conditions: reviewing the seabed strata, understanding the undulation of the seabed surface and the thickness of the accumulation layer; Review the seabed sediment to determine whether erosion construction should be carried out and bury it at the required depth; Inspect the seabed obstacles to understand if there are any obstacles hindering the burial construction