Microwave absorption and dielectric spectral detection technology with high time resolution (1 ns) is used for contactless measurement of electron property in solid materials. In this paper, the free photoelectron time-resolved spectra of cubic AgCl emulsion sensitized by green-sensitizing dye are measured by dielectric spectral equipment. The samples are exposed to 35-ps short pulse laser at 355 and 532 nm, respectively. The results show that for the same sensitized sample, the free photoelectron lifetime are 43.1 and 5.8 ns, respectively. And for the same wavelength, the lifetime of sensitized emulsion is shorter than that of pure emulsion. It is thus proved that the adsorption of dyes to silver halide microcrystals increases the Ag_(i)+ concentration.