In order to achieve displacement measurement of low cost

easy processing and high-precision

timegrating displacement sensor of light field coupling is designed. The measurement principle of displacement sensor

which uses electric standing waves based on alternating light field to synthesize electric traveling wave signal

and achieves spatial displacement conversion by means of phase discrimination

is illustrated; structural design of sensor is completed

system block diagram is given and function of signal processing circuit is specifically analyzed. Experimental results show that measurement error of time-grating displacement sensor of light field coupling can reach to ± 0. 5 μm at range of 108 mm.