Optoelectronic tweezers is a new kind of particle manipulation technology based on dielectrophoresis.Light pattern is projected onto a photoconductive layer with the photoelectric effect,and then virtual electrodes is generated on the layer,to manipulate particles.Compared with traditional dielectrophoresis manipulation,the most obvious feature of the optoelectronic tweezers is virtual electrode;it can be flexible controlled by graphics software.Through software,optical pattern can form on anywhere of the photoconductive layer,so as to achieve flexible control.Experimental system and working principle of optoelectronic tweezers are expounded,research progress and application in micro-nano manipulation are introduced.