The utility model discloses an independent basin formula liquefied gas carrier, it includes: hull, cargo tank and only superficial device. The cargo tank is located in the cabin of hull. It includes spacing subassembly and float assembly to end superficial device. On float assembly was fixed in the horizontal bulkhead of cargo tank, on spacing subassembly was fixed in the horizontal bulkhead of cabin, spacing subassembly was located float assembly directly over, and spacing subassembly is including the spacing flat board that is used for restricting the float assembly rebound. The spacing subassembly that is located on the horizontal bulkhead of cabin cooperatees with float assembly on the horizontal bulkhead that is located the cargo tank, has prevented the cargo tank come -up effectively. The horizontal bulkhead of cabin is higher with the intensity and the rigidity of the horizontal bulkhead of cargo tank, can be under the condition of additionally not carrying out the structure enhancement to the satisfied strength requirement that only floats of device is floated in ending of less quantity, thereby has simplified liquefied gas carrier's structure, has reduced the cost.