Pulse modulation width (PWM) of multi-phase inverter is the key technologies of ships electrical propulsion. In this paper, theories and realization of space vector PWM (SVPWM) for five-phase inverter is analyzed. The proposed SVPWM adopts two adjacent large voltage vectors to composite the reference voltage vector and this method have advantages of easy to realize. Theoretical waveform and harmonics of five-phase inverter output voltages under the proposed control method are deduced. The analysis shows that there are very large third harmonics in the inverter output voltages and currents. The total harmonic distortion (THD) is large also, and changes small with the modulation index. Simulation and experiments certify the conclusions.