The invention discloses a fixing yoke applicable to compatible mounting of single and double gas cylinders of a transfer trolley. The fixing yoke comprises a yoke assembly supporting arm, a yoke base, a first rotating shaft, a second rotating shaft, a first locking rod, a second locking rod, a first yoke clamping plate, a second yoke clamping plate and a fastening belt, wherein the yoke assembly supporting arm comprises a yoke assembly supporting arm body, a handle and a plurality of yoke assembly supporting arm pores; a first groove body and a second groove body are formed in the yoke base; the first groove body is connected with a first locking rod clamping groove, and the second groove body is connected with a second locking rod clamping groove; the first yoke clamping plate is connected with the yoke base through the first rotating shaft, and the second yoke clamping plate is connected with the yoke base through the second rotating shaft. With the adoption of the fixing yoke, the gravity center stability of the transfer trolley equipped with single gas cylinder is improved, and the compatible switching of two gas cylinders and single cylinder in mounting can be achieved.