The existing calculation method is cumbersome for the weight calculation of long-term group of suspended-modular tram. In order to study the new method of weight distribution calculation, the 7-module 100% low floor trams were taken as the research object. Based on the articulated structure between adjacent vehicles of floating type trams and the statically indeterminate theory, the tram body and its installation equipment were simplified as rigid bodies, and by adopting the virtual displacement principle, the static balance equation of the rigid system was derived, and the stress state of different vehicle bodies was analyzed with the deformation coordination principle, and the axle load and wheel weight of the vehicle are calculated. A computer program was written to parameterize the method, and the calculation results were compared with the finite element method. The results showed that the calculation method was reasonable and effective, and could be applied to the weight management of 100% low floor tram design process.