Disclosed are a compatible circuit and a terminal. The compatible circuit includes a printed circuit board (PCB) of which the existing structure is not changed, and a group of compatible devices which are in a pin-to-pin form and have different internal structures, wherein the compatible devices and the PCB are assembled together; the internal structures of the compatible devices are matched with a link compatibility selection requirement; and the compatible devices are configured to conduct link selection output on at least two links which are input and need compatibility, in accordance with the link compatibility selection requirement.