Abstract: Composite adhesive-bonded repairs are efficient and cost-effective means of the technology of composite repairs. Analytical model for double lap joints of composite laminates was established and the model contained the details of stepped end. Maximum strain criterion was adopted for predicting failure load by composite laminates. Maximum shear strain criterion and damage area criterion were applied by adhesive to predict failure load. The residual function was defined to represent the distance of the ultimate load between analytical results and test results for composite double lap joints. Both ultimate load and equivalent stiffness of analytical model were verified by tests. Compared to the experimental data, analytical results show the following points:Ultimate load of double lap joints of composite laminates almost grows monotonously with the increase of lap length. Analytical equivalent stiffness has a better agreement with the test results, and its maximum error is less than 15%. The residual value of ultimate load on damage area criterion reaches a minimum value to 4.30% when the damage characteristic length is 4%. The residual value of ultimate load on maximum shear strain criterion is 6.41%. With the increasing of lap length, the ultimate load upon analytical results indicates three stages:swift growth, slow growth and scarce growth. Considering the structural weight and other factors, lap length should choose from 15 mm to 35 mm.