Obstetrical pelvis measurer

The utility model provides an obstetrical pelvis measurer, which relates to the technical field of obstetrical and gynecological equipment and comprises a sleeve, a fixing block is mounted on one side of the sleeve, a mounting cavity is formed inside the fixing block, a shaft pin and a connecting shaft are connected inside the mounting cavity, a ratchet wheel is sleeved on the outer side of the shaft pin and is positioned inside the mounting cavity, and the connecting shaft is connected with the connecting shaft. The outer side of the connecting shaft is sleeved with a pawl, the pawl and the ratchet wheel form a ratchet wheel mechanism, a connecting block is installed on one side of the installing cavity, and a first spring is connected between the connecting block and the pawl. Through cooperative use of the ratchet wheel and the pawl, the movable handle can only rotate in the direction away from the fixed handle, so that the situation that the movable handle retracts due to external force is prevented, a me