The invention discloses a nickel-based composite catalyst for methane reforming with carbon dioxide to produce a synthesis gas under pressurization. A carrier of the catalyst is at least one selectedfrom SiO2, Al2O3 and TiO2, an active component is Ni, Ni-Fe or Ni-Co, and an auxiliary agent is one selected from composite oxides such as CeO2-La2O3, CeO2-Sm2O3, CeO2-Pr6O11, CeO2-Nd2O3 and CeO2-Y2O3; based on a mass of the catalyst of 100%, the catalyst comprises 5%-15% of the active component, 3%-15% of the auxiliary agent, and the balance of the carrier; and the catalyst is prepared by adopting a coordination-decomposition method with glycine, alanine, threonine, citric acid and oxalic acid as a coordination-combustion improver. The catalyst disclosed by the invention has a simple preparation process and lower costs, and is economic and environmentally friendly; and the catalyst has a higher methane and carbon dioxide conversion rate for methane reforming with the carbon dioxide underthe pressurization, exhibits high activity, high stability and extremely high resistance to carbon deposition and sintering.