In order to facilitate the synthesis of nickel phyllosilicate through the hydrothermal method, different process parameters including high or low hydrothermal temperature, single or double solvent, and with or without accelerator were investigated in this work. The Ni/DA-150-6 catalyst prepared in the presence of double solvent and the accelerator exhibited high Ni content, small Ni crystal size, and large H2 and CO2 chemisorption capacity, leading to the highest catalytic activity for CO2 methanation. Meanwhile, Ni/S-200-12 synthesized by the high-temperature (200 °C) hydrothermal method or Ni/D-150-12 prepared at 150 °C in the presence of double solvent displayed low catalytic activity owing to the low Ni content. In short, the synergistic effect of double solvent and accelerator is the most significant strategy for the efficient synthesis of Ni-phyllosilicate.