This invention discloses a composite panel, its preparation method, and its application, belonging to the field of building panel technology. The composite panel comprises, from the outside to the inside, a decorative layer, an anti-warping reinforcement layer, a foamed core layer, and a balancing layer, with a
thermal expansion release structure at the edge. The anti-warping reinforcement layer uses a high-modulus
glass fiber mesh to improve the panel's stiffness and suppress bending deformation; the balancing layer and decorative layer form a symmetrical structure to offset bending stress caused by temperature gradients; the
thermal expansion release structure allows for micro-displacement of the panel to release thermal stress. This invention, through the
synergy of the anti-warping reinforcement layer, the balancing layer, and the
thermal expansion release structure, can effectively reduce the warping deformation of exterior wall cladding under thermal
cycling conditions, while also possessing advantages such as
weather resistance,
thermal insulation, lightweight, and environmental friendliness. The preparation process is simple, suitable for large-scale production, and can be widely applied to composite
imitation stone exterior wall cladding.