When optical imaging in turbid media, the target signal is drowned in the background noise due to the influence of media absorption and scattering, resulting in a serious degradation of image clarity. As a representative technique of polarization imaging, polarization differential can significantly improve the detection capability of targets in turbid media by using the polarization information of light, which fully exploits the difference in polarization characteristics between medium light and scene light to achieve polarization common-mode suppression of backscattered noise. Due to its simple system structure, good portability, wide range of applicable fields, highlighting the edge and other advantages have attracted much attention. This technology can not only be used as a physical optical imaging method for high contrast imaging of targets in underwater turbid environments, biological tissues, and atmospheric haze scattering environments, but also as an effective means to suppress stray light from optical sensor devices, and a large number of excellent research results have been accumulated since its introduction. From the basic principle of polarization differential imaging technology, according to the different imaging application scenarios, a series of recent research advances in polarization differential imaging is introduced from two aspects. And an outlook on polarization differential imaging is provided, which provides guidelines for subsequent research in this field.