According to the hydrogenation characteristics of mixed long chain α-olefin, Ni/γ-Al2O3 was prepared using Dry Impregnation (DI) with γ-Al2O3 serving as the carrier. Both the catalyst and the raw material were characterized using TEM and BET to investigate the relationship between the pore size of the catalyst and the particle size of the mixed olefin. The results show that the catalyst can effectively reduce the resistance of olefin entering the catalyst channel and eliminate the effect of internal diffusion. In order to further optimize the performance of the catalyst, Charge Enhanced Dry Impregnation (CEDI) was employed to enhance the catalyst performance. The results showed that the catalytic performance of the catalyst prepared by CEDI was doubled compared with that of DI. Analysis through XRD, SEM, and TEM revealed that the Ni nanoparticles in Ni/γ-Al2O3 prepared by CEDI are well-dispersed on the carrier, exhibiting a particle size of approximately 5.0 nm and demonstrating excellent catalytic activity. Additionally, XPS confirmed the strong metal-carrier interaction in Ni/γ-Al2O3, which imparts resistance to sintering and coking at the active site during the hydrogenation of long-chain olefin, thereby ensuring good stability.