Abstract: In order to improve the ratio of effective load to wing mass (load/mass ratio) of all-composite wing, a finite element simulate approach was proposed to predict the ultimate load of all-composite wing, and the structural design framework which can raise the structural efficiency of wing was established. First, based on the thin-walled engineering beam theory, theoretical analysis was conducted on all-composite wing, and the initial design of structure form and lay-ups form for all-composite wing was preceded. Then, based on the testing data of initial wing, four kinds of different finite element models were built using ABAQUS, and the best numerical simulate approach was obtained by contrast. After that, fourteen kinds of structure configuration forms were established and each structure form were given with different lay-up plans, thus one hundred and seventeen design plans for wing were formed, the load/mass ratios and manufacture factors of each structure form were contrasted. Finally, the all-composite wing was manufactured and test verification was conducted. The results show that double I-beam structure is the best structure configuration form of wing, which has relatively high load bearing efficiency. The relative error between simulated load and testing value is only 1.91%, which verifies the correctness of finite element model. The load/mass ratio of wing reaches 24.17 N/g, which is 30.65% higher comparing with that of the initial design. The conclusions obtained show that the design approach is valid.