The all-optical wavelength conversion (AOWC) based on orthogonal dual-pump for polarization multiplexing signal in semiconductor optical amplifier (SOA) is investigated. The influence of laser line-width on the performance of all-optical wavelength conversion is theoretically investigated, and the transmission performance of polarization-multiplexing-orthogonal-frequency-division-multiplexing (PM-OFDM) signal in the system is simulated. The simulation results show that when the optical signal-to-noise ratio is 10 dB, the polarization insensitive signal can be received as two light waves without crosstalk as a result of four-wave mixing effect for 10 Gbit/s PM-OFDM signal propagating in the SOA, and the bit error rates are 1.16×10-4 in x-direction and 1.06×10-5 in y-direction, respectively. Meanwhile, the simulation results indicate that laser line-width, number of sub-carriers of OFDM signal, channel power, and modulation format, obviously influence the AOWC conversion efficiency. The theoretical derivation is well consistent with the simulation result.