Abstract: Objective: To investigate the effects of different fermentation conditions on Ophiopogon japonicus fermentation liquid moisturizing function, to obtain the optimum fermentation process. Method: Single factor test was used to adjust fermentation parameters such as the preparation method of fermentation substrate, Ophiopogon japonicus concentration, inoculum, fermentation temperature, fermentation time and rotational speed with the moisture retention of the Ophiopogon japonicus fermentation liquid. Optimization of fermentation parameters of Ophiopogon japonicus based on response surface method, studied the moisture retention of the obtained fermentation liquid of Ophiopogon japonicus. Result: The optimum fermentation process of Ophiopogon japonicus liquid was obtained,and the fermentation liquid of Ophiopogon japonicus has the better moisture retention. Conclusion: Ophiopogon japonicus fermentation liquid has good moisturizing properties and can be used in cosmetic raw materials.