Objective: this study focuses on improving the water solubility of coconut oil and expand its application in food industry. Methods: According to the characteristics of the solubility of coconut oil, soybean lecithin - deoxycholate was used as shell material with coconut-oil core to establish coconut-oil bile salt liposomes by thin film dispersion method. Response surface optimization (RSM) was carried out according to the encapsulation rate, and the effects of several factors, including soybean lecithin/deoxycholate ratio, PBS/ anhydrous ethanol ratio, sample fat ratio, ultrasonic time, hydration time and hydration temperature, on the encapsulation rate were investigated. Results: The results showed that the optimal preparation conditions were soybean lecithin/deoxycholate salt ratio of 2.53, sample fat ratio of 0.56, hydration temperature of 64.7 ℃, and the encapsulation efficiency of coconut oil bile salt liposomes was 58.09%. Conclusion: The encapsulation efficiency of coconut oil bile salt liposomes made by thin film dispersion method is favorable, and can improve the water solubility of coconut oil.