The invention discloses an FPGA (field programmable gate array)-based infrared image detail enhancing system and method. The system comprises a bilateral filtering module, a gaussian filtering module, a histogram projecting module and an automatic gain control module, wherein the bilateral filtering module is connected with the gaussian filtering module which is connected with the histogram projecting module and the automatic gain control module respectively, and original input data firstly passes through the bilateral filtering module to obtain image pattern fundamental frequency information; the fundamental frequency information passes through the gaussian filtering module to be smoothened, and differencing is carried out between a result and the original input data so as to obtain image detail information; and the detail information is amplified by the automatic gain control module, the fundamental frequency information is compressed by the histogram projecting module, and the detail information and the fundamental frequency information are summed to obtain an output image. According to the invention, the contrast ratio of the image can be improved, the detail information can be enhanced, background noise can be restrained, and the common problems that the edge is fuzzy and a visual effect is poor in the image of a thermal infrared imager imaging system in the prior art can be solved.