Aiming at the vibration noise of thin plate existing in the engineering, a topology optimization method of the stiffener location distribution was proposed in this paper. The velocity dynamic response of the structure was analyzed by the finite element method, and the obtained results were substituted into the acoustic power equation deduced from the acoustic radiation mode to get the acoustic power. The topology optimization mathematical model considering the stiffener location as the design variable was established to find the stiffener location with minimum acoustic power. The starting points of stiffener and the search process were determined by the acoustic radiation modal sensitivity. The simulation result shows that the optimized stiffener distribution can effectively reduce the vibration noise by 7.38 dB. The influence of the convergence criterion and different frequency on the stiffener distribution was discussed. The proposed method can be used for optimizing the structure topology within the first natural frequency.