To improve calculation efficiency of the coupled vibration between random traffic flow and bridge, an innovative time domain analysis method is proposed. The traffic-bridge coupled vibration equation is established by combing the modal synthesis technology and global analysis method. The dimension of motion equation for random vehicles and bridge system is updated constantly based on the progress evaluation for the running vehicles on the bridge, and the algorithm of dynamic storage and extraction for procedural computing data is proposed. The whole framework and detailed implementation steps also are introduced for the proposed traffic-bridge coupled vibration analysis method. Numerical results indicate that the computing cost of the proposed method is 14.5% of the traditional integral method, and it is similar with the separated iterative method when relative errors are less than 3.5%. The proposed method has a good computing efficiency and accuracy, and can be used to the random traffic load and bridge coupled vibration analysis.