Forming device and forming method for large-wall-thickness annular composite product

The invention provides a forming device and method for a large-wall-thickness annular composite product. The forming device comprises an annular mold and an auxiliary layer. The auxiliary layer is paved along the inner ring surface of the prepreg paving layer on the innermost side in the at least one prepreg paving layer; wherein any prepreg laying layer, of which the fiber orientation is consistent with the annular direction of the forming molded surface, in the at least one prepreg laying layer needs to be laid in a segmented manner along the annular direction; wherein the auxiliary layer comprises a plurality of laminated plates, and every two adjacent laminated plates in the plurality of laminated plates are laid on the inner ring face of the prepreg laying layer on the innermost side in a staggered and segmented mode in the annular direction. Therefore, the forming quality of a large-wall-thickness and large-size annular composite material structure prepreg laying layer formed by the female die and an au