The online dynamic balance detection of various tires calls for the multi rim combination method. In light of measurement differences, the dynamic model of the test machine was improved considering the rim width. The common calibration algorithm based on the least squares complex number influence coefficient calibration method was analyzed. The unbalance equivalent algorithms under different rim diameters and widths were derived. The mechanical locking device was designed according to the tire specification parameters. In addition, the servo system realized the online rim width adjustment. The experimental results and engineering applications verify the feasibility and validity of the algorithm.