Reverse balance flange,which has found wide applications in the industry of wind power,is a new type connection form of huge tower tube.The reverse nalance flange of main tower tubes used in the 750 kW wind turbines of No.65 and 66 in Diaobing Mountain Wind Power Field are taken as the test objects.Scale tests of two reverse balance flanges and these connected tower tube were performed under static load.The results show that reverse balance flange has excellent bending stiffness; the ultimate carrying capacity of this connection is above 1.5 times as large as the design load.Neither local buckling nor fracture of the pipe in the joint was observed in the tests.It is proved that the reverse balance flange can meet the requirements on strength and rigidity under the designed load and has high emergency capacity.