In this paper, shrimp and crab waste was used as raw material for extraction of astaxanthin. The subcritical fluid extraction process was optimized. Result shows that the best extraction reagent, temperature, pressure, static time and static cycle were dichloromethane, 100℃, 9.31-11.72MPa, 15 minutes and 2 times, respectively, under which the extraction ratio is 0.0373%. Compared with the result of traditional organic solvent extraction, the subcritical fluid extraction has 33.2% higher extraction ratio and consumes 82.8% less time.