Infrared dim target in complex background is difficult to detect due to low brightness,small size and few available features.How to suppress background clutter and improve the target signal to noise ratio in detection has become a hot and difficult research area in this field.In this paper,the evolution and performance of small target enhancement and background suppression technologies based on contrast mechanism of human visual system are summarized and analyzed.The development of local contrast measurement window from single scale to multi scale,and even dynamic or adaptive scale,meets the need of rapid synchronous detection of small targets of unknown size in applications.The calculation methods of local contrast measure change from simple to complex,based on low order information to using high order information,which is conducive to more comprehensive suppression of complex background and further enhancement of the target.Therefore,it will become the future direction for small target detection algorithms for human visual contrast mechanism.