Due to the special operating environment of Marine cables, higher and higher spatial resolution and temperature resolution are required for existing distributed optical fiber temperature measurement systems. However, in the distributed optical fiber temperature measuring system based on Raman scattering demodulation, the spatial resolution, temperature resolution, temporal resolution and temperature measuring distance are mutually restricted. To design a temperature measuring system for meeting the on-line monitoring requirements of the ship power system, the influencing factors of the spatial resolution of the system are analyzed. On this basis, the equivalent model of distributed optical fiber temperature measurement system based on the optical time domain reflection technology is formulated, and the priority of each influencing factors is obtained. A more accurate influence model of system temperature resolution is deduced, which is based on the Raman scattering light intensity formula. Finally, the interaction formula among spatial resolution, temperature resolution, temporal resolution and temperature measurement distance is achieved, which provides a reference for the design of performance index of the distributed fiber temperature measurement system. By further increasing the accumulation times and decreasing the pulse width of pump light, the spatial resolution can be improved while ensuring the spatial resolution and temporal resolution in a short measurement distance. An experimental platform is established to evaluate the proposed method. By adjusting the accumulation times and pulse width in 500 m temperature distance, the temperature resolution is 0. 65℃ , the spatial resolution is 1 m, and the temporal resolution is 1 s.