The invention relates to molybdenum/titanium/silver metal layered composite material used for space and a preparation method thereof. The composite material comprises a layer of pure molybdenum foil; two layers of pure titanium foils; and two layers of pure silver foils, wherein the foils are laminated into a similar "sandwich" structure according to the order of the pure silver foil, the pure titanium foil, the pure molybdenum foil, the pure titanium foil and the pure silver foil and connected as a whole, and the molybdenum-titanium interface and the silver-titanium interface are chemically and metallurgically bonded. The preparation method comprises the steps that a combined blank material of the similar "sandwich" structure is formed by orderly lamination; hot rolling composite connection is performed on the combined blank material, and annealing processing is further performed under the atmosphere of inert gas after hot rolling; and the molybdenum/titanium/silver metal layered composite material used for the space is obtained after annealing. The composite material has great space environment adaptability, thermal conductivity, electrical conductivity and weldability so as to meet the requirements of the space electronic packaging application; and the preparation method of the composite material realizes formation through hot rolling composite connection so that the manufacturing technology is simple, the quality is stable and controllable, operation is convenient and large-area automatic roll-to-roll batch production can be realized.