The present application provide a pixel circuit and a driving method thereof, and a display panel. The pixel circuit includes: a driving module, a control end of the driving module being electrically connected to a first node; a threshold compensation module, electrically connected to a first scan signal line, the first node, and a first end of the driving module; a first switch module, electrically connected to a first light emitting control signal line and the first end of the driving module; a second switch module, electrically connected to a second light emitting control signal line, a second end of the first switch module, and a first electrode of a light emitting element; and a voltage regulator module, electrically connected to a constant voltage signal line and a target node.