The utility model relates to switch equipment in a power system and discloses an outdoor high-voltage isolating switch with high reliability. The outdoor high-voltage isolating switch comprises a rectangular frame, wherein the two ends of the frame are provided with a left fixed porcelain bottle and a right two fixed porcelain bottle; and the top ends of the two fixed porcelain bottles are provided with wiring copper bars. The outdoor high-voltage isolating switch is characterized in that two guide rails are oppositely arranged at the inner sides of two long side plates of the frame; two trolleys are installed between the two guide rails and are assembled with driving devices; the two trolleys are respectively provided with a left sliding porcelain bottle and a right sliding porcelain bottle; a pair of sliding contact switches are installed at the top ends of the two sliding porcelain sliding porcelain bottles; and the left half and the right half of the sliding contact switches are respectively connected with the wiring copper bars on the left fixed porcelain bottle and the right fixed porcelain bottle one by one in a flexible connection way. In the utility model, the four problems of contact overheating, porcelain bottle breakage, movement clamping, poor switch-in and switch-out are completely solved; moreover, the outdoor high-voltage isolating switch is mainly used for isolating the part required to be power off and the electrified part in a high-voltage power distribution device reliably, thereby ensuring the safety of overhauling.