The invention relates to the technical field of tunnels, in particular to a meshless method for analyzing excavation and support of a tunnel. The method comprises the following steps of (1) starting CAE of ABQUS, and establishing a two-dimensional model of a chamber; (2) dividing a triangular cell model; (3) outputting a model file, Job-1. Inp; (4) starting MATLAB, opening a main program file, Main_Program. M, of MFVM; (5) reading the model file, Job-1. inp; (6) generating node information; (7) using the MFVM to calculate the initial ground stress of surrounding rocks; (8) calculating a stress field and a displacement field in the first step of the excavation. The method has the advantages that since an approximation function of the meshless method has no dependence on meshes, the difficulty caused by grid distortion is reduced, interface connection with CAD software can be achieved more easily, and the method is suitable for solving large-scale scientific and engineering problems; besides, since the adaptability of the meshless method is very strong, node position information rather than mesh information is needed in the pretreatment of the meshless method, and a complex three-dimensional structure can be analyzed easily; moreover, an obtained graph of meshless calculation is smooth and continuous, so no stress smoothing is needed.