In order to study the characteristics of the films deposited by pulsed plasma thruster plume and assess contamination arising from the exhaust plume, the compositions of the pulsed plasma thruster plume are studied by means of mass spectrum analysis, the structural properties of the films deposited at different angles on the cathode side of the thruster are investigated by X-ray photoelectron spectroscopy, Fourier transform infrared absorption spectroscopy, and the optical properties of the films are studied by ultraviolet-visible light spectrophotometry. The results show that the plume consists primarily of C, F, CF, CF2, CF3, that low fluorine-carbon ration carbon fluorine films are deposited by pulsed plasma thruster plume, and that the chemical bondings and structures of these films present different trends in different regions with 30 degree angle as the boundary. These films basically show that they have strong absorption properties for wavelengths below 500 nm and have enhanced reflective characteristics. Due to influence of the characteristics of the deposited films, the optical properties of these films present signigicant angular dependences.