The all-optical wavelength conversion technology plays an important role in WDM networks and there have been mature theoretical study on the Semiconductor Optical Amplifier（SOA）-based all-optical wavelength conversion technology.However

it still has a lot of deficiencies in its performance.This paper analyzes and compares the principles and performances of SOA-based all-optical wavelength conversion technologies in different structures and types from the most basic ones to the improved technical schemes and looks into their application prospect and development orientations.The results show that we can improve the performance parameters of all-optical wavelength conversion technology in different aspects by changing the gain characteristic of SOA or system structures.