The invention discloses a combined-type high-
voltage conversion switch which comprises a double-power-supply switching device and a vacuum
circuit breaker, wherein the double-power-supply switching device comprises a main power supply post, an auxiliary power supply post, a wire outlet column; and the vacuum
circuit breaker comprises a wire inlet terminal, a wire outlet terminal, a vacuum
extinction mechanism and an operation mechanism. The double-power-supply switching device also comprises a main vacuum
extinction mechanism electrically connected with the main power supply post and an auxiliary vacuum
extinction mechanism electrically connected with the auxiliary power supply post; the switching operation mechanism comprises a driving mechanism with a driving arm, a lever and an
interlocking mechanism which is used for synchronously driving the switch-on and switch-off motions of the main vacuum extinction mechanism and the auxiliary vacuum extinction mechanism; the driving arm in the driving mechanism is connected with one end of the lever in a rotation mode, and the other end of the lever is connected with the
interlocking mechanism; and the wire inlet terminal of the vacuum
circuit breaker is electrically connected with the wire outlet terminal in the double power supply switching device. According to the invention, the time required for double-power-supply switching is shorter, and the double-power-supply switching is approximate to non-time-difference switching.