The invention provides a lateral embedding-piece structure of a product with an inward-concave structure on the inner wall. The product with the inward-concave structure on the inner wall can be formed in a mold for one time, so that the accuracy of the product is improved and the production efficiency of the product is improved. The lateral embedding-piece structure comprises a front mold, a rear mold, a rear-mold embedding piece, a plate A and a plate B, wherein a cavity is formed among the front mold, the rear mold and the rear-mold embedding piece; the product is arranged in the cavity; the inner wall of the product is provided with the inward-concave structure. The lateral embedding-piece structure provided by the invention is characterized in that a lateral embedding piece is arranged in the inner wall of the product; an outer circle surface of the lateral embedding piece clings to the inner wall of the product; the tail end of the outer side of the lateral embedding piece is provided with an integral inclined surface; the integral inclined surface of the outer side of the lateral embedding piece clings to the lateral inclined surface of a shovel machine; an inclined guide column penetrates through an inclined guide groove of the lateral embedding piece; the lateral embedding piece specifically comprises an upper-part front-end embedding piece, an upper-part rear-end embedding piece, a middle-part embedding piece and a lower-part embedding piece.