The present invention provides a method for oil extraction from dehydrated Euphausia superbas, which is related to the field of food biotechnology. The method combines a low temperature and low oxygen heat pump dehydration system with a microwave-assisted frozen-blasting dehydration system for Euphausia superba dehydration, resulting in formation of a large number of micro porous structures in dehydrated Euphausia superbas that is good for subsequent oil extraction. The dehydration and extraction process can be separated in the present invention. The low temperature and low oxygen heat pump dehydration system may be installed in shrimp boats to dehydrate Euphausia superbas before transportation so as to increase the effective payloads of shrimp boats. The extraction process of subcritical fluid assisted with ultrasonic operation is carried out under low temperature and low oxygen conditions, therefore the oxidation of active ingredients is avoided to a large extent. Compared with existing methods, the present invention not only possess excellent dehydration efficiency but also uses less time and energy.
