The corrosion and blockage in pipes has influenced on pipe wall thickness variation. This paper proposes frequency domain response function to evaluate the pipe wall thickness. System field matrix by continuous and momentum equations is derived, and the evaluation model of the pipe wall thickness is based on frequency response function. The position of pipe wall thickness change and length of wall thickness varying are evaluated by pressure response function in frequency domain (h) and the number of peak (m). The theoretical equation is verified by the field experiment, and estimation error is less than 4%. Meanwhile, the degree of wall thickness change directly affects the resonant peak shift, and frequency response model can be used to evaluate current pipeline status