Abstract: The present disclosure provides an etching method, a manufacturing method of a thin film transistor, a process device and a display device. The etching method includes: forming a patterned photoresist layer on the surface of a material to be etched, the patterned photoresist layer exposing an area to be etched on the surface of the material to be etched; curing the photoresist layer by adopting a plasma process; and etching the material to be etched by adopting an etching solution corresponding to the material to be etched. The present disclosure can help to solve the problem of undercutting and improve the product yield and product performances.