The utility model relates to the field of geothermal wellhead devices, and provides a concentric double-pipe geothermal wellhead device with a testing function. The tubing head comprises a bottom flange, a tubing head cross joint, a hanger, a valve, an upper flange gland, an upper flange body, a pup joint, a tee joint and a hoop connector, wherein the hanger consists of an outer pipe hanger for hanging an outer pipe, an inner pipe hanger for hanging an inner pipe, a hanger connecting pipe and a protective screw, the outer pipe and the inner pipe are concentric, and an injection channel and a test channel are arranged on the upper flange body and the outer pipe hanger. Double-pipe concentric suspension is achieved, a heat insulation pipe is replaced with the method that heat preservation media are injected into the annulus of the pipe column, and the extraction cost is reduced; a test channel is designed, a test pipeline carries a test instrument to go deep into a well from the test channel, and the well bottom temperature, stress and the like are detected in real time.