Manifold mounting and positioning device and method for steel cylinder protection underwater production system

The invention relates to a steel cylinder protection underwater production system manifold mounting and positioning device and method, and the device comprises two guide male heads which are fixedly connected to the inner wall of a round steel cylinder according to a set included angle, and the guide male heads are arranged in the axial direction of the round steel cylinder; the two guide female heads are connected to the two guide male heads respectively, and the guide female heads are configured to freely slide on the guide male heads in the axial direction, but movement in other directions is limited; one end of at least one piece of supporting square steel is connected with the guiding female head in a fastened mode, and the other end of the supporting square steel extends in the radial direction of the steel cylinder and is connected with a manifold base disc to be positioned in a fastened mode. The device can be prefabricated on land and installed on the sea, extra construction facilities are not needed