Abstract: The purpose of this study was to explore the new way of comprehensive utilization of Periplaneta americana discards.With P.americana discards as raw material and petroleum ether as extraction solvent,the process conditions of ultrasonicassisted extraction of residual oil were optimized by orthogonal test.The effect of ultrasonic power,extraction duration,liquid to solid ratio and times of extraction on yield of residual oil were investigated．Furthermore,the oil was prepared using sulphuric acid as catalyzer through reaction of ester exchange with methanol,the preparation conditions were optimized through orthogonal experiment,and the effects of reaction temperature,reaction time,molar ratio of methanol to oil and catalyst amount on oil conversion rate were investigated.The results showed that the optimal extraction conditions of oil were obtained as follows:ultrasonic power of 300 W,extraction duration of 0.5 h,solid to liquid ratio of 1:8 and extracting for 4 times.Under the optimal extraction conditions,the yield of oil reached 24.25%．The optimal transesterification conditions were:reaction temperature of 65 ℃,reaction time of 2.5 h,molar ratio of oil to methanol of 1:6,catalyst amount 1.5% of oil weight.Under these conditions,the oil conversion rate was up to 94.37%.

Key words: discards of herbal medicine, comprehensive utilization, Periplaneta americana, oil, biodiesel