The invention relates to a swing preventing device for launching and retrieving processes of marine
underwater survey equipment. A fixed seat is mounted on a
deck of a survey vessel, a frame body is hinged to the fixed seat, one end of a
hydraulic cylinder A is hinged to the fixed seat, the other end of the
hydraulic cylinder A is hinged to the frame body, a fixed
pulley is arranged on the frame body, one end of a
rope is connected to the fixed seat, and the other end of the
rope passes through the fixed
pulley to be connected to a to-be-launched-and-retrieved marine
survey instrument; a clamping arm fixing plate is hinged to the frame body, one end of a
hydraulic cylinder B is hinged to the frame body, and the other end of the hydraulic cylinder B is hinged to the clamping arm fixing plate; and a hydraulic cylinder C is mounted on the clamping arm fixing plate, connecting rod mechanisms hinged to the clamping arm fixing plate are arranged on the left side and the right side of the output end of the hydraulic cylinder C correspondingly, the connecting rod mechanism on each side is connected with the output end of the hydraulic cylinder C, the other end of the hydraulic cylinder C is a clamping end for clamping the marine
survey instrument, and the connecting rod mechanisms on the two sides are driven by the hydraulic cylinder C to be opened or clamped. According to the swing preventing device, swing of the marine
survey instrument in the launching and retrieving processes is thoroughly prevented, and safety of marine scientific investigation operators is ensured.