As a flexible structure,the response of suspension bridges under live load has been the focus of research for a long time.This paper presented an analytical calculation method for structural deformation and internal force of suspension bridges under concentrated live load.Based on the known bridge state parameters and live load parameters,the deformation of the main cable,the deformation of the main beam,the relationship between the main cable and the main beam,and the deformation of the bridge tower were analyzed successively.Then,four kinds of governing equations were established,involving the conserved unstrained length of each main cable,the coordinated force and deformation of each suspender,the closed span and height difference,and the balanced force of the main beam,so that the total number of the governing equations was equal to the total number of basic unknown parameters.Finally,the governing equations were combined into an objective function and solved programmatically.The values of the basic unknown parameters were found to make all the governing equations valid at the same time,and then all the other parameters were deduced.The state of the structure after deformation was expressed.Finally,a suspension bridge with a main span of 1 080 m was taken as an example to verify the feasibility and effectiveness of the method.The results of deformation and internal force under live load were in good agreement with those of the finite element method.