As a passenger carrying component, the vibration level of railway vehicle carbody directly influences the ride comfort of passengers. For the vertical elastic vibration suppression of railway vehicle carbody, the traditional technology mainly focuses on the design of carbody modal frequency, the method of increasing damping and the design of dynamic vibration absorber, with little attention to the design of modal shape. So, a novel vibration suppression method based on the control of modal shape node is proposed in this paper, that is, by adjusting the weight distribution of carbody along the length direction to achieve the purpose of controlling the first-order vertical bending modal shape node positions, so that the nodes can be close to the carbody-bogie interface locations to reduce the modal generalized force, and then the carbody vertical elastic vibration is suppressed. The traditional carbody model with uniform cross-section Euler-Bernoulli beam is replaced by variable cross-section beam model, and the influence of the weight distribution on the modal frequency and modal shape node position of the carbody is studied. At last, the full-scale railway vehicle roller rig is used for the vibration suppression method verification. The theoretical analysis and experimental results show that: by reasonable designing the weight distribution of the carbody, the modal shape node position of first-order vertical bending mode can be controlled, and then combined with the bogie distance design, the vertical bending elastic vibration of the carbody can be suppressed effectively.