A miniature fiber Bragg grating (FBG) temperature sensor with a galvanized sensitization copper film and a seawater corrosion-resistant carbon film is designed by the electroplating process and the magnetron sputtering. When the seawater temperature within the range of 0~50 ℃, the Bragg wavelength of the FBG temperature sensitization sensor is linear with the seawater temperature, and the linear coefficient is nearly 99.99%. The temperature sensitivity can be precisely controlled by the electroplating time and the electric current. The properties of temperature and the seawater corrosion-resistance of the three kinds of sensing probes, e.i., the probe with copper plating film, the probe with copper and carbon plating film, the probe with copper and silica plating film, are analyzed. The results show that the temperature sensitivity coefficient increases exponentially with the copper film thickness, and the copper film thickness increases linearly with the plating time. The carbon film with the diamond-like structure can inhibit the corrosion of the sensitization copper film in seawater.