From the Optoelectronic Integrated Circuits (OEIC), according to the rate equations of carriers transition and the equations of optical field propagation in Quantum Dot Semiconductor Optical Amplifiers(QD-SOA), an equivalent circuit model of QD-SOA was established. Based on the circuit simulation method, the gain spectrum and saturated gain characteristics of QD-SOA were simulated and analyzed. The characteristics of wavelength conversions at the rates of 40 Gbps, 100 Gbps and 160 Gbps were studied based on the Cross Gain Modulation (XGM) of QD-SOA respectively. Meanwhile, the effect of signal light and probe light with different bias current and power on the properties of the output signal, including the extinction ratio and Q factor, was analyzed. The rate of wavelength conversions can reach 100 Gbps, Extinction Ratio(ER) is about 10 dB and Q factor is about 2.2. This study is quite important for improving the performances of wavelength conversion based on XGM of QD-SOA.