Cardanol acetate (CA) was synthesized with bio-based cardanol reacted with acetic anhydride catalyzed by toluene sulfonic. The second step, that is, cardanol acetate (CA) was epoxidized by hydrogen peroxide as a clean oxidant and formic acid was deployed as catalyst. Herein, the influences of several related factors on the epoxy value of product, such as the concentration of hydrogen peroxide (H2O2), the amounts of formic acid and hydrogen peroxide, reaction temperature, and reaction time were discussed. Based on aforementioned rules, the optimum condition was concluded as follows: 70 % H2O2, n (formic acid) : n (H2O2) : n (the amount of double bond in CA)=0.2 : 1.5 : 1, the reaction temperature was 65 oC and the reaction time was 6 h. Furthermore, the epoxy value of the final product under present condition was 6.8 % and a yellow transparent oily liquid was obtained. Simultaneously, the acid value, heat weight loss, viscosity and TG curves of the product were also investigated, respectively. As a result, ECA can satisfy the requirements of plasticizer.