By taken extraction efficiency of carotenoids from Cordyceps militaris as an index, six different extraction approaches were compared for selecting the best one, they were heat acid extraction technique, ultrasonic wave extraction technique, heat acid-ultrasonic wave extraction technique, microwave extraction technique, heat acid microwave extraction technique and acetone extraction technique. The results showed that heat acid-ultrasonic wave extraction technique was the better one for extract carotenoids in C.militaris . The optimum approach was adopted to conduct six single-factor experiments, including HCl concentration, time of soaking in HCl, heating time, ultrasonic power, ultrasonic extraction temperature and ultrasonic extraction time, then the L27(313) orthogonal test was designed to optimize the extraction conditions. Results indicated that the extraction efficiency could reach up to 1 134.88 μg/g under these conditions, they were the 2.25 mol/L concentration of HCl, 30 min of soaking time in HCl, 400 W of ultrasonic power, 6 min heating time, 25 ℃ ultrasonic extraction temperature and 25 min ultrasonic extraction time; These conditions ranked as follows in turn: ultrasonic power, time of soaking in HCl, HCl concentration, heating time, ultrasonic extraction temperature, ultrasonic extraction time.