Rapid and efficient desorption of CO2 from produced liquid has become a key issue which is addressed urgently in the gathering and transporting system of CO2 drive oilfield in China. Main theories of gas desorption are introduced and the features of traditional desorption technology, membrane desorption technology and ultrasonic desorption technology are analyzed in this paper.On the basis of which, defects of all kinds of desorption technologies are pointed out, and the direction of the gas desorption research is proposed. In addition, research progress of ultrasonic desorption, based on the self built experimental device of ultrasound promoting the gas desorption from the CO2 drive produced liquid, is introduced. Then, the combination of the new desorption technology and the traditional desorption is suggested to be applied to the CO2 desorption of produced liquid.