PURPOSE: To provide the wet-type molding method of a curved surface board that is capable of molding an inorganic curved surface board efficiently in a short period of time in a state of restraining the amount of water absorption, and a curved surface forming mold frame capable of being preferably employed in molding a curved surface board by this wet-type molding method.

CONSTITUTION: On the mold frame of a female mold 1 or the like equipped with an approximately semicircular recessed-bight surface 1a formed as a curved surface having a predetermined curvature, a laminated body 7 is placed which comprises a water-absorbed gypsum board 5 and a veneer board 6 merely superimposed on one surface or both surfaces of the gypsum board 5, and the bending means of the female mold 1 or the like is brought into contact with respect to the laminated body 7, which serves to impart bending forces to the laminated body until the laminated board at least abuts on the crooked surface of a male mold 4, and by the bending means and the aforementioned mold frame, a curved surface having a predetermined curvature is formed on the gypsum board 5. The mold frame used herein contains a pair of male and female mold frames 1,4, and on respective both side peripheries 1b of an opening of the female mold 1, small diameter rolls 2 are rotatably disposed that each has a rotational axis parallel to the side periphery, and the outer peripheral surface in the inside of each small diameter roll 2 is aligned on the extension of the tangential direction in the periphery of a curved surface of the female mold.