The free photoelectron signals of spectral sensitized AgCl emulsion with different sensitization concentrations are obtained from microwave absorption dielectric spectrum experiment. It is found that when sensitization concentration is small (0.04 mg dye per 40 g AgCl emulsion) or great (4 mg dye per 40 g AgCl emulsion), the decay of free photoelectron of sensitized emulsion is slower or faster than that of pure emulsions; when sensitization concentration is between the above values (0.4 mg dye per 40 g AgCl emulsion), the decay of free photoelectron is the same for sensitized and pure emulsion. The results indicate that the adsorbed green-sensitizing dye on the surface of cubic AgCl microcrystals takes on different actions with different sensitization concentrations.