In order to develop an anti-infrared and 1064nm laser filter wit efficient electromagnetic shielding functionbased on the induction theory of metal film and the interference principle of multilayerthe influence of thickness error of Ag film on the spectral properties of filter is discussed. The dielectric films were deposited by ion beam assisted depositionand the metal Ag film was deposited by ion beam sputtering. The thickness of Ag film can be precisely monitored by means of enlarging the film thickness control errors. And the oxidation of Ag film can be avoided. The transmittance of the filter at 1064nm is over 88%the reflectivity of mid-long wave infrared band is over 90%and the shielding effectiveness of the filter at 18~36GHz is over 23dB. The filter has good shielding function of mid-long wave infrared and electromagnetic.