Abstract: Along with the fast development of market economy and the deepening power regulation reform, the competition among the power supply companies becomes fierce. Meanwhile, the mergers and acquisitions become more frequently. To promote the efficiency and the success rate of the merger and acquisition, the technical due diligence may contribute to it. The author fortunately participated in a typical merger and acquisition of a power supply company, as a member of the technical due diligence team. The technical due diligence evaluated the power assets to be taken over, which were divided into eight aspects including power system planning, electric primary, electric secondary, civil, transmission lines, communication and power distribution network. The outcome was acceptable to for both the acquirer and the acquiree, making the acquisition work smoothly. It may also serves as an example for the future mergers and acquisitions in power industry. Therefore, in a merger and acquisition where technical threshold exists such as power industry, a technical due diligence is necessary apart from financial, law, and land property due diligences, which can offer a technical risk assessment and some probable rectification measures to the acquirers.