Abstract: To solve the polarization problem of semiconductor laser, a method of fabricating periodic gratings on GaAs substrates by displacement Talbot lithography (DTL) exposure technology is proposed, and the influence of process parameters and anti-reflection layer on the quality of the exposed periodic gratings is systematically studied. The secondary photolithography process and the reactive ion etching process are used to prepare the circular hole array periodic grating on the GaAs substrate; the uniform grating is manufactured by inductively coupled plasma etching (ICP) equipment. Experimental results show that this process can prepare a dynamic adjustable circular hole array periodic grating with a depth of 20-150 nm; when the exposure dose is 30 mJ·cm^-2, the exposure light intensity is 2 mW·cm^-2, and the development time is 1 min, the exposed periodic grating meets the experimental requirements; Repeated experiments proved the feasibility and stability of using DTL to prepare the grating process.