In order to improve the light transmission efficiency and to decrease the overlay of tricolor output spectra of a color filter, a 2D submicron embedded grating with a broadband width and high transmission efficiency was proposed.The device is consist of such four parts as a PMMA substrate, a ZnS layer, a metal submicron grating and a SiO2 layer.By the Rigorous Coupled-wave Theory (RCWT), the effects of the structural parameters on the spectral transmission characteristics were discussed, then three broadband color filters with its full width at half maximum (FWHM) about 100 nm were obtained by optimizing the structural parameters.For the red,green,blue color filters with the center wavelengths of 635 nm, 530 nm and 455 nm,their corresponding transmission efficiencies are 68%,78% and 71%， respectively.The numerical results show that the transmission efficiency has increased about 19% as compared to those of previous color filters, while the overlay of the tricolor output spectra is decreased effectively and the transmission characteristics are improved.