The invention belongs to the technical field of molecular electronic devices, and in particular relates to an electrically reversible molecular electronic device based on scanning tunneling microscopy technology and a manufacturing method thereof. This molecular electronic device consists of a substrate, an organic molecular layer, and a probe. Among them, the substrate adopts an atomically flat conductive surface, the probe adopts a needle tip in a scanning tunneling microscope, and the organic molecular layer is a vertically oriented monolayer. The organic molecules are elongated π-conjugated molecules containing polar groups. This molecular electronic device can be reversibly switched with an external forward and reverse pulse voltage, that is, it can be erased and written, and can be read with a very low operating voltage. The molecular electronic device of the invention can be used as an electrically erasable ultra-high-density memory, a molecular switch, a logic element, etc., and has wide application value in molecular computers.