The structure of a grating polarizer in common 1053 nm lasers was optimized for high power laser systems. The diffraction characteristics and extinction ratio of the grating polarizer were investigated by using rigorous coupled-wave theory. The results show when the grating period, duty cycle and the groove depth of the grating are 600 nm, 0.535-0.55 and 1 395-1 420 nm at a wavelength of 1053 nm, respectively, the extinction ratio could be more than 1500, and the optical transmittance of the TM-polarized wave could be over 95%. Based on the above analysis, a high quality photoresist grating mask was made by holographic lithography. Then, it was transferred to the fused silica substrate by tilted rotating ion beam etching and reactive ion beam etching to fabricate a grating polarizer with the period of 600 nm, bottom duty cycle of 0.54 and the groove depth 1 400 nm. Experimental measurements on the grating polarizer show that the optical transmittance is 92.9% and the extinction ratio is 160. Compared with other fabricating methods for the grating polarizer, the proposed method only requires a single layer of photoresist grating mask, which simplifies the fabricating process, enjoys low costs and guarantees the high damage threshold of the grating. As the method can fabricate large scale gratings, it is suitable for applications to the high power laser systems.