A forming method of a large-aperture thick-wall short-radius high-temperature alloy bend comprises the steps that (a) tool preparation is conducted, specifically, medium-frequency induction heating ring preparation is conducted, a cooling water spraying hole is formed, and pressing tool mold preparation is conducted; (b) blank preparation is conducted, specifically, a roller tube free of UT and PT defects is selected; (c) medium-frequency bending is conducted, specifically, a tube blank is placed into a medium-frequency tube bending tool, and the frequency is selected in a lowest mode within a standard range to conduct pushing; (d) discharging is conducted, specifically, according to the back arc length size of a target product, a bent tube subjected to pushing is sawed into the bends, burrs at the two ends are removed; and (e) normal-temperature reshaping is conducted, specifically, a lubricating agent is painted on the contact surfaces of the bends and a mold in advance, the bends are placed into a lower mold, inner core molds are put into and orderly arranged at intervals, a closed mold is pressed on a four-column pressing machine, after completing, the inner core molds are taken out, and thus forming of the large-aperture thick-wall short-radius high-temperature alloy bend is completed. A plurality of tools and a plurality of times of pressing are not needed, a forming technology is simplified, the machining difficulty is simplified, the mold is avoided form losing stability, the bending quality is improved, and the forming method is suitable for forming of the large-aperture thick-wall short-radius bend.