With the development of aerospace manufacturing and high-performance aircraft, large-curvature plate-shell structure has been widely used. Aiming at the problem of assembly deformation caused by factors such as prestress and size and position deviation. a fiber Bragg grating sensor is used to study the surface reconstruction algorithm of plate-shell structure. The relationship between wavelength shift and curvature is established, and the curvature data required for the surface reconstruction algorithm is obtained. Segment fitting algorithm is applied to calculate the coordinate increment of all measuring points to realize the curve reconstruction. On this basis, the measured surface of the plate-shell structure is reconstructed, and the theoretical data at the measuring points of the ANSYS simulation surface is compared with the data of the actual reconstructed deformation surface. The results show that the algorithm is highly effective and provides technical support for the deformation prediction and modification of plate-shell structures.