The invention relates to a high-voltage switch and a double-acting transmission system thereof. The high-voltage switch includes a double-acting transmission system. The double-acting transmission system includes a first pull rod and a second pull rod. The second pull rod is a power input rod in transmission connection with an operating mechanism. The opposite ends of the first pull rod and the second pull rod are respectively connected with a first contact and a second contact. The first pull rod and the second pull rod are in transmission connection through a transmission structure. The transmission structure includes a fixed frame, a crank arm of which the middle is hinged to the fixed frame, a first connecting rod of which the two ends are respectively hinged to the inner end of the crank arm and the first pull rod, and a second connecting rod of which the two ends are respectively hinged to the outer end of the crank arm and the second pull rod. When the second pull rod of the double-acting transmission system moves in a direction under a push/pull force, the second pull rod is driven by the transmission structure to move in an opposite direction. The first pull rod and the second pull rod respectively drive the contacts connected therewith to move in opposite directions for opening or closing. Through simultaneous movement of the two contacts, the opening/closing speed ofthe high-voltage switch is greatly increased.