The existing panel acoustic contribution analysis method is improved and a method of analyzing and estimating acoustic contribution of panel vibration to the acoustic field is proposed. In the n-dimensional vector space, total sound pressure vector is expressed as a linear combination of its frequency components, and with the ratio of field point sound energy to the whole acoustic field sound energy as weighted coefficient, the contribution to field point total pressure is summed up to represent the panel acoustic contribution to the entire acoustic field. Taking an ambulance for example, acoustic contribution of compartment panels vibration to internal acoustic field is analyzed and panels of larger contribution are identified with this method, and the results are confirmed through the comparison of noise reduction effects of two kinds of damping treatment. On the basis of analysis result, the damping treatment is applied to the ambulance, and the low-frequency noise of multiple field points is effectively reduced.