In order to achieve the miniature and integration of the optical devices in multi-wavelength array detection, a novel transmission filter based on subwavelength metallic grating guided mode resonance is proposed. The resonance characteristics of the filters with symmetric and nonsymmetric waveguide structure are theoretically analyzed. The effects of the grating structural parameters on the transmission spectrum are investigated in detail, such as filling factor, grating thickness, the sidewall angle, et al. And the optimal scope of the grating structure is also presented. Simulation results show that the peak position and the full width at half maximum (FWHM) of the filter are attributed to the grating period and the buffer layer. And the FWHM can be adjusted from 2 nm to 45 nm, the maximum transmittance increases to 81.7%. Besides, the transmission spectrum is independent on the polarization of the incident field due to the symmetry of the subwavelength metallic grating. The filters can satisfy the requirements of microfluidic and biosensing and so on.