Tunnel boring machine (TBM) vibrates strongly under rock breakage forces. In this paper, a vibration mechanism analysis of TBMs is presented considering the influences of excitation, structure and boundary conditions. Also, the challenging issues in TBM dynamic modeling for vibration analysis is discussed. Furthermore, the study of the vibration characteristics of TBMs based on vibration data from field test is proposed to help dynamic modeling. The test system, the distribution of measurement points and the way to collect data are determined for the field vibration test under tunneling sceneries. Vibration acceleration data is obtained from a field test in an actual tunneling project and dynamic characteristics of TBM is analyzed based on the collected acceleration data. The results show that the root mean squares of vibration acceleration at the measurement points near main bearing and motors reach 20~30 m/s2, those at main beam and grippers reach 3~6 m/s2. The peak frequencies of cutter head driving system are much higher than those of support-thrust system, and the vibrations of sub-structures of TBM are multi-mode coupled. Vibration mechanism of TBM is revealed by the field test, providing a reference for dynamic modeling, theoretical or numerical analysis, and vibration reduction of TBMs.