Supercritical CO2 fluid extraction technology was used to extract camptothecin from Camptotheca acuminate seeds. With the preconditions of CO2 flux 20 L/h, the effect of different parameters such as extraction time, temperature, extraction pressure and entrainer on the supercritical carbon dioxide extraction of camptothecin was investigated. The optimum technological conditions were validated by orthogonal experiments design: extraction press 25MPa, temperature 50℃, extraction time 120 min, and entrainer 90% ethanol. Under the optimal conditions, extraction rates of camptothecin was 76.98%, content of camptothecin was 43.68% in crude extracts.