The invention provides a vibration analysis method for a uniform section beam structure. The method comprises the steps that geometric size characteristics of the beam structure are extracted, a displacement field of the beam structure is separated to be in-section displacement and axial displacement; fitting is performed on the in-section displacement of the beam structure; extension is performedon the axial displacement of the beam structure; the in-section displacement and the axial displacement of the beam structure are combined to calculate integral displacement of the beam structure; strain vectors and stress vectors of an elastic plate structure are calculated; strain energy, a kinetic energy equation and boundary energy of the beam structure are calculated; a structural Lagrange energy function is established to obtain a core mass matrix and a stiffness matrix of the beam structure; an integral mass matrix, an integral stiffness matrix and an overall mass matrix are solved through iterative looping of the core matrix, and then a characteristic equation of the structure is obtained; and a characteristic equation matrix of the beam structure is solved, and inherent frequencyand a vibration mode are obtained through calculation. The method is suitable for the beam structure with multiple boundary conditions and multiple section shapes and is high in precision, fast in convergence, low in calculation cost and simple in calculation method.