Objective To optimize the formulation of the sunscreen used in military training.Methods The different formulations of sunscreen were prepared according to the orthogonal design,and then applied on 3M adhesive tape posted on the color dish with a certain amount;the absorbance in 280 nm-320 nm and 320 nm-400 nm of them were measured and the arithmetic mean (A) was concluded.By comparing A,the protective effect and the main factors affecting preventive bask were determined.The preventive bask test of the optimum formula was carried out in human trials using the method of multi point increasing ultraviolet irradiation.Results OMC,TinosorbTM M,rutin,pearl powder and baicalin all had significant effects in preventing UVA.OMC had a significant effect in preventing UVB.The formula 1 (containing the five materials mentioned above) had the best effects in preventing both UVA (SPF 18) and UVB (PA+).Conclusions The formula 1 has the best effects in preventing both UVA and UVB.