A fastening component free from electrochemical corrosion includes a first fastening plate, a second fastening plate, and a fastening screw connecting them. A screw shaft of the fastening screw is penetrated through a first fastening hole of the first fastening plate and entered the second fastening hole of the second fastening plate. A head of the fastening screw is abutted against the first fastening plate and is sleeved with an isolation member for electrochemical corrosion protection. The isolation member includes an annular spacer located between the lower end face of the head and the first fastening plate, and a first segment surrounding the side wall of the head and connected to the annular spacer, and upper end face of the first segment is higher than or flush with the upper surface of the first fastening plate or the upper end face of the head in a smaller height.