The hydrogenated product of tricyclopentadiene (TCPD) is a potential high-energy-density fuel. The hydrogenation pathway of TCPD was investigated to understand the reaction process. The reaction intermediate and final products were characterized by using GC-MS, IR, 1H NMR and 13C NMR. The double bond in norbornene ring (NB bond) of TCPD was easily saturated at a low temperature, and an intermediate 12, 13-dihydrotricyclopentadiene (12, 13-DHTCPD) was formed. Higher temperature and hydrogen pressure were required for the saturation of remaining double bond in cyclopentene ring (CP bond) to generate a completely hydrogenated compound tetrahydrotricyclopentadiene (THTCPD). That is to say, the reaction occurred via the TCPD→12, 13-DHTCPD→THTCPD route. To clarify the reactivity of double bonds in TCPD molecules, a DFT calculation at B3LYP/6-31G* level was conducted by using Gaussian 03 series programs. The bond parameters confirmed that the NB double bond was more reactive than the CP bond. Total energy calculation also showed that 12, 13-DHTCPD was preferred in thermodynamics, compared with another possible intermediate 5, 6-DHTCPD. The computational result was in good agreement with the experiments. This work provides fundamental information for the two-step hydrogenation operation of TCPD.