A method for transporting an offshore turbine in a floating manner comprising the following steps: a frame construction is mounted on a deck of a transportation and installation ship, the frame construction is coupled with a hydraulic device capable of control extension or retraction of the frame construction; and the periphery of the frame construction is provided with a locating hole; a wind turbine foundation is prepared in advance on land; said wind turbine foundation is of a semi-closed cylinder with an opening defined in its bottom portion; its top cover has a diameter no less than the shortest side length of the frame construction; a plurality of hoisting points are evenly distributed on the top cover of the wind turbine foundation; the locations of these hoisting points correspond to locations of the locating holes defined in the frame construction; a vent hole is defined in the top cover of the foundation; the top portion of the wind turbine foundation is connected to a hollow transition segment; the largest diameter of the transition segment is smaller than the shortest side length of the frame construction such that the segment is able to pass through the frame construction; the wind turbine foundation connected with the transition segment is disposed into water by hoisting, delivered by floating manner to the transportation and installation ship, and the transition segment is extended out of the frame construction; a hoisting device is provided on the transportation and installation ship at a location corresponding to a hoisting point on the top cover of the wind turbine foundation; the steel wire of each hoisting device passes through the locating hole defined in the frame construction and is connected with a corresponding hoisting point of the wind turbine top cover; the wind turbine is inflated via the vent hole defined in the top cover thereof until the top cover of the wind turbine is tightly pressed against a lower portion of the frame construction; the respective steel wire is tightened by respective hoisting device such that the wind turbine foundation is temporarily secured with the frame construction; the wind turbine tower, wind turbine head and blades are hoisted in turn and then are assembled to form an entire wind turbine machine; and a flexible auxiliary retention mechanism is disposed on the upper portion of said wind turbine tower, and the entire wind turbine machine is conveyed to the installation place. a frame construction is mounted on a deck of a transportation and installation ship, the frame construction is coupled with a hydraulic device capable of control extension or retraction of the frame construction; and the periphery of the frame construction is provided with a locating hole; a wind turbine foundation is prepared in advance on land; said wind turbine foundation is of a semi-closed cylinder with an opening defined in its bottom portion; its top cover has a diameter no less than the shortest side length of the frame construction; a plurality of hoisting points are evenly distributed on the top cover of the wind turbine foundation; the locations of these hoisting points correspond to locations of the locating holes defined in the frame construction; a vent hole is defined in the top cover of the foundation; the top portion of the wind turbine foundation is connected to a hollow transition segment; the largest diameter of the transition segment is smaller than the shortest side length of the frame construction such that the segment is able to pass through the frame construction; the wind turbine foundation connected with the transition segment is disposed into water by hoisting, delivered by floating manner to the transportation and installation ship, and the transition segment is extended out of the frame construction; a hoisting device is provided on the transportation and installation ship at a location corresponding to a hoisting point on the top cover of the wind turbine foundation; the steel wire of each hoisting device passes through the locating hole defined in the frame construction and is connected with a corresponding hoisting point of the wind turbine top cover; the wind turbine is inflated via the vent hole defined in the top cover thereof until the top cover of the wind turbine is tightly pressed against a lower portion of the frame construction; the respective steel wire is tightened by respective hoisting device such that the wind turbine foundation is temporarily secured with the frame construction; the wind turbine tower, wind turbine head and blades are hoisted in turn and then are assembled to form an entire wind turbine machine; and a flexible auxiliary retention mechanism is disposed on the upper portion of said wind turbine tower, and the entire wind turbine machine is conveyed to the installation place.