The invention relates to an improved power supply facility for charging at a public place. The power supply facility comprises a power supply base fixedly installed on the wall; a central slot is formed in the power supply base; a first sliding slot that extends up and down and is communication with the central slot is formed in the upper end wall of the central slot; a sliding bar is installed inthe first sliding slot in an up-down sliding manner; an inner thread groove with the opening upward is arranged in the sliding bar; and a thread rod is installed in the inner thread groove in a screw-thread fit and is in power connection with a lifting motor fixedly installed in the top wall of the first sliding slot. A conductive sleeve fixedly connected with the lower end of the sliding bar isinstalled in the central slot; and a plugging slot is formed in the conductive sleeve in a front-back communication manner. Second sliding slots extending up and down are formed in the power supply base in a left-right symmetric manner; sliding blocks are installed in the second sliding slots in an up-down sliding manner; grooves are formed in the end surfaces, facing the central slot, of the sliding blocks; and oblique extruded surfaces and limiting end surfaces are arranged at the grooves.