The invention discloses a catalyst and a catalytic process for preparing higher olefins adopting MCM-41 as a carrier and assisted by microwaves. The catalyst for directly preparing higher olefins frommethane with assistance of microwaves is a nickel-molybdenum composite catalyst adopting MCM-41 as a carrier. The catalytic process comprises the following steps: under the conditions of microwave assisted heating and induction and excessive hydrogen, firstly performing catalytic dehydrogenation coupling for the methane by virtue of nickel powder, then performing the catalytic polymerization by virtue of the nickel-molybdenum composite catalyst, rectifying purifying a polymerization product, performing the polycondensation for the product under the effect of heating and the nickel-molybdenumcomposite catalyst, and high selectively synthesizing higher olefin liquid fuel. By adopting the natural gas or biological methane as an initial raw material, the method has the characteristics of high selectivity of higher olefins, environmental friendliness, energy conservation, low cost, nontoxicity of catalyst, and no pollution and is a process route with a promising prospect for preparing thehigh-octane-number gasoline liquid fuel.