In order to satisfy the complex detection demand of space optoelectronic systems, a prepared method of waveguide-gate film electron multiplying structure based on micro channel plates applied in the field of space complex detection was proposed. From the view point of photomultiplication of micro-channel plates and modulation and distributary of space electron beam, operation principles of this detector and some constraints during the preparation process are explained. After the effects of different incident beam energies and different thickness of gate films on trajectories of incident electrons in waveguide-gate films are respectively studied on the basis of a physical model from scattering of low-energy incident electronics in multiplex dielectrics, process characteristic parameters of the gate are targeted in the range by simulation results. A free-standing organic film is prepared on the micro channel plate through water drawing. And an aluminum film is deposited on the organic film by means of resistance thermal evaporation after optimization. As a result, the complex gate films are achieved within nanometer thickness. Besides, the structure of the complex gate is given characterization through visual means. At last, for the aspect of the function about complex detection ,the feasibility of the gate film complex detector is verified by experiments through a special test system in a vacuum chamber.