Fiberglass reinforced plastic (FRP) composite symmetric laminates are orthotropic at the macroscopic level, and the transverse bending problem of such plates is usually analyzed and calculated using classical laminated plate theory. The classical laminated plate theory is a widely used practical engineering theory due to its simple mechanical models and mathematical problems. This theory is based on the assumption of Kirchhoff's elastic thin plate theory, where the transverse shear strain is assumed to be zero, that is, the transverse shear stiffness C=is considered, and the low ratio of shear stiffness C to bending stiffness D is a material characteristic of composite materials. Obviously, the mechanical model of classical laminated plate theory is far from the actual material properties. Accurate elastic theory analysis shows that for general composite laminated plates, when the span thickness ratio a/h>40, the calculated results of classical laminated plate theory are in good agreement with the actual deformation. Therefore, for thicker composite laminates, it is necessary to consider the influence of shear deformation to improve analysis accuracy.