Pulsed laser deposition technology, which is considered to be one of the best method for preparing function films, has the large development potential and broad application. It′s indicated that: mostly all the films could be prepared by pulsed laser deposition technology; most of pulsed laser depositions are carried out by excimer laser with the wavelength of 248 nm whose photon energy is high, and most of films are prepared by single laser in the gas and heater condition; the films prepared by pulsed laser deposition are amorphous or polycrystalline, and a few of single crystal films are prepared just in the condition of very high temperature and vacuum. On the base of the characteristics of this technology, the pulsed laser deposition system with magnetic filter technology is designed and founded to supply the technology and hardware base for improving the performances of function films prepared by pulsed laser deposition.