The invention relates to switch equipment in a power system, in particular to a high-reliability outdoor high-voltage isolation switch. The isolation switch is provided with an oblong-shaped frame, wherein a left fixed porcelain bottle and a right fixed porcelain bottle are arranged at the two ends of the frame; and copper busbars are arranged at the top ends of the two fixed porcelain bottles. The isolation switch is characterized in that: two guide rails are arranged oppositely on the inner sides of two long side plates of the frame; two trolleys are arranged between the two guide rails; a driving device is arranged; a left sliding porcelain bottle and a right sliding porcelain bottle are arranged on the two trolleys respectively; a pair of sliding contact switches is arranged at the top ends of the two sliding porcelain bottles; and the left half and the right half of the pair of sliding contact switches are flexibly connected with the copper busbars on the fixed porcelain bottles on the left and right sides. Four problems such as overheat of a contact, fracture of a porcelain bottle, motion clamping stagnation, insufficient switch-on and switch-off and the like existing in the conventional isolation switch are solved completely; and the isolation switch is used for reliably isolating a part which is required to be switched off from an electrified part in a high-voltage power distribution device, so that maintenance safety is ensured.