A series of sulfur-free Ni/gamma-Al2O3 catalysts with different metal Ni loading amount were prepared by impregnation method. The prepared catalysts and corresponding precursors were investigated through XRD, BET, H-2-TPD, and H-2-TPR analysis methods. The effect of Ni loading on catalytic performance of Ni/gamma-Al2O3 catalysts was evaluated by methyl laurate catalytic hydrodeoxygenation (HDO). Results indicate that the catalytic HDO performance of the prepared Ni/gamma-Al2O3 catalysts was directly related to hydrogen storage properties, hydrogen desorption properties, dispersion of the active component Ni, and so on. The 10 wt.% Ni/gamma-Al2O3 catalyst exhibits the best HDO performance, and the methyl laurate conversion can reach 91.1% when the reaction temperature is 400 degrees C and pressure is 2 MPa. The HDO products are alkanes, such as C (< 10), C-10, C-11, C-12 alkane, C-12 alcohol, and C-12 acid, especially. The main product C-11 alkane with one carbon less is formed by decarbonylation/decarboxylation, and selectivity can reach 68.6%. The effects of reaction conditions on HDO reaction of oils were studied, for example, reaction pressure and H-2/Oil ratio. The catalyst retains comparable activity upon regeneration through calcination and H-2 reduction.