The invention relates to the technical field of oil production engineering of oil fields and belongs to a preset cable well downhole self-generating electricity and cable butting technology. The problem that in the preset cable well operation process, cable binding and cable protector mounting needs to be conducted outside a chuck distance is solved. Intelligent water distribution devices (3), cable packers (4) and tool section cables (2) of downhole power source management devices (6) are connected through oil pipes (9); after completion pipe string putting is completed, a self-generating electricity device (8) and a downhole cable butting device male head (7) are connected through the cables and put from a wellhead; the downhole cable butting device male head (7) is connected with a downhole cable butting device female body (1) in an inserted mode; and the situation that all the parts from the wellhead to the tool section cables (2) are within the oil pipes (9) is achieved. The preset cable well downhole self-generating electricity and cable butting technology has the advantages that the risk that the cables are damaged in the construction process is avoided, and the communication and power supply of downhole tools are guaranteed.