Provided are a display panel, a plasma etching method and a system. After patterning a metal film layer on a substrate with a chlorine-containing gas, a post-treatment for suppressing corrosion is implemented by using plasma containing an oxygen-containing gas and a hydrogen-fluoride-containing gas. Thus, the surface of the metal film layer is an aluminum ion-containing crystal, which solves the technical problem of corrosion of the aluminum layer in the plasma etching technology of the prior art.