In order to accomplish the high temporal-spatial resolution and continuous measurement of the ocean temperature-depth profile, a new measurement system of combining ship towing application and optical fiber sensing technology was developed. The fiber Bragg grating (FBG) pressure sensors were integrated into the temperature drag chain for the first time, so as to obtain the depth information and judge the drag chain attitude. The development of the towing temperature-depth chain system and the situation of the sea trial were introduced, including the system equipment and the laboratory calibration results of pressure sensor before sea trial and static and dynamic test of pressure sensor at sea. The correlation coefficient of pressure sensor and ALEC Compact-TD reaches 0.999 837 and the measurement error was less than 0.1 m by analyzing the test data, which further verifies that the towing temperature-depth chain system has been initially available.