A wide-range positive-negative adjustable high-voltage DC power supply includes the following components: a high-voltage generator, a negative high-voltage terminal, and a positive high-voltage terminal; a first driving circuit, a first voltage regulating unit, a current detection and amplification circuit, a second driving circuit and a second voltage regulating unit that are connected in turn; and an adjustable high-voltage output terminal; as well as an instruction input terminal, an instruction voltage circuit and an error amplifier that are connected in turn, and a voltage feedback circuit.