The present invention relates to a method for carrying out separation extraction on cottonseed oil and shortening a cottonseed oil separation extraction time by adding an extremely hydrogenated vegetable oil as a crystallization promoting agent, and uses of the extremely hydrogenated vegetable oil as the crystallization promoting agent in cottonseed oil separation extraction. According to the present invention, the extremely hydrogenated vegetable oil is added as the crystallization promoting agent during the cottonseed oil separation extraction process so as to shorten the cottonseed oil separation extraction time and obtain the liquid cottonseed oil meeting the liquid cottonseed oil freezing test requirements in GB1537-2003 (the oil sample maintains the clarified and transparent state for more than 5.5 h at a temperature of less than 0 DEG C), such that the time and the energy source cost are saved, and the economic benefits of the enterprise are improved.