The invention relates to a connector, in particular to an underwater connector for offshore drilling. The underwater connector for the offshore drilling comprises a connector housing, a connecting upright pipe, a carrying disc and elevating hydraulic cylinders, and is characterized in that the connector housing sleeves the connecting upright pipe, the carrying disc is fixedly mounted at the top of the connecting upright pipe, a plurality of elevating hydraulic cylinders are fixedly mounted at the circumference of an upper surface of the connector housing, and the elevating hydraulic cylinders are fixedly connected with the carrying disc through piston rods. The connector has the advantages of simple structure and reliable connection; in operation, pre-mounting initial positioning of the connector and a wellhead device is realized through three guide pins, and sealed connection between the connecting upright pipe and the wellhead device is realized by pressing and clamping of the respective hydraulic cylinders, the entire mounting process is completed through operation of an ROV (Remote Operated Vehicle) without needing a diver, and the underwater connector for the offshore drilling is particularly applicable to quick connection and use of the upright pipe and the wellhead device in the offshore drilling process.