Abstract: For simulation and testing of the radial acoustic modes of aero-engine fan pipe, the simulation and identification methods of the radial acoustic modes are studied. The radial mode sound source is simulated by adjusting the amplitude and phase of each loudspeaker preset in the array. The multi-cycle ring array downstream of the sound source pipeline is established, and the transfer function matrix of the mode is constructed according to the position information of the array. The Tikhonov regularization method is used to reduce the number of conditions of the transfer function matrix, so as to realize the capability of radial acoustic mode recognition. Through theoretical deduction and numerical calculation, the radial acoustic mode test device of fan pipe is designed and verified in anechoic chamber. The experimental results show that the system has the ability to simulate and identify radial acoustic modes within 4 circumferential order 4 and radial order 2.