Long-term monitoring method applicable to deflection deformation of beam of historic building

The invention relates to a long-term monitoring method applicable to deflection deformation of the beam of a historic building. The long-term monitoring method is characterized by comprising building a finite element (beam columns and tenon-and-mortise nodes) model for a historic wooden building to be monitored by using finite element software and simulating deflection deformation of a beam; performing error analysis by using an improved conjugate beam method to determine the best unit partition quantity of the beam; dividing the beam to be monitored into units having equal length according to the best unit quantity, and then working out deflection deformation value of the beam by using a fiber bragg grating strain sensor and the improved conjugate beam method. According to the long-term monitoring method applicable to deflection deformation of the beam of the historic building, the used instruments are strong in corrosion resistance and stability; the method has small disturbance to the historic building, an