The helicopter emergency flotation system can provide flotation capability after the helicopter accidentally falls into the water. During a test of a helicopter float in a submerged state, it was found that the vertical distance between the highest point of the contact point of the float and the aircraft and the lowest point of the cabin door was 0.59 m, which seriously hindered the entry and exit of the crew from the cabin door. To reduce the adverse effects of the pontoon flipping up on the occupants entering and exiting the hatch, it is envisaged to use restraint belts, add anti-rollover airbags, and design the anti-rollover airbags into triangles and saddle shapes respectively. Through theoretical analysis, the simulation method eliminated the triangle method for the connecting belt and the anti-rollover airbag and selected the saddle-shaped anti-rollover airbag for floating and immersion tests. The test results met expectations. The highest point of the contact point between the float and the aircraft was the lowest point of the cabin door. The points did not interfere in the vertical direction, and this method was finally chosen to be applied to the buoy to suppress the upturn of the buoy.