The characteristics of coal tar rich in aromatic hydrocarbons give it the feasibility of preparing high-performance jet fuels,and the hydrogenation saturated products of fused-ring aromatic compounds (such as perhydrophenanthrene) can significantly enhance the thermal stability of jet fuels. The key point to realize this process is to prepare high performance hydrogenation saturation catalyst. In view of the adsorption problems in the saturation reaction of phenanthrene hydrogenation,based on the special electronic structure of Ni2P,in order to strengthen aromatics adsorption as the goal,the composite oxide carrier Al2O3-TiO2 was prepared by sol-gel method,and a series of Ni2P/Al2O3-TiO2-phenanthrene hydrogenation saturation catalyst were prepared by the hypophosphite decomposition method. The effects of different content of TiO2 on the geometrical structure,electronic structure and phenanthrene hydrogenation saturation of Ni2P catalyst were investigated. The results show that when the reaction temperature is 320 ℃,the reaction pressure is 5 MPa,and the WHSV is 52 h-1),contrast with Ni2P/Al2O3 catalyst,the conversion of phenanthrene do not changed (95%),while the selectivity of perhydrophenanthrene over Ni2P/Al2O3-TiO2 (15% TiO2)）is increased from 49% to 68%. Meanwhile,the turnover frequency was also improved from 0.3 s-1 to 0.7 s-1. The geometric structure and electronic structure of the catalysts were analyzed,and it is found that TiO2 can deliver the appropriate amount of electrons to the Ni in Ni2P catalyst,and so that Ni in Ni2P is in a suitable electron deficient state,which will enhance the adsorption capacity of Ni2P/Al2O3-TiO2 catalyst for phenanthrene and intermediate products. Moreover,the doping of TiO2 is beneficial to the formation of Ni2P with smaller particle size. When TiO2 doping amount is 15%,Ni2P has the smallest particle size (4.3 nm) in the catalyst,which can provide more active sites for hydrogenation reaction and make the catalyst have strong phenanthrene hydrogenation saturation capacity.