The invention provides a multi-purpose digital display circuit comprising a digital-to-analog converter N1, an MCU single-chip microcomputer N2, a liquid crystal module N3 and a precise reference chip N4. The MCU single-chip microcomputer N2 and the digital-to-analog converter N1 are connected by DOUT, /CS, DIN, SCLK, and /SYNC wires; the liquid crystal module N3 and the MCU single-chip microcomputer N2 are connected by a reading-writing control wire R/W, a data/command control wire RS, and a data wire D0-D7; a digital power supply DVDD of the digital-to-analog converter N1 is in power supply connection to the MCU single-chip microcomputer N2, the liquid crystal module N3 and the precise reference chip N4; the output terminal VOUT of the precise reference chip N4 is connected to an REFIN(+) pin of the digital-to-analog converter N1; and a grounding terminal of the precise reference chip N4 is connected to an REFIN (-) pin of the digital-to-analog converter N1. The multi-purpose digital display circuit has the following beneficial effects: precision requirements on analog-to-digital conversion by various universal measuring and displaying instruments can be met; and the circuit has advantages of small size, excellent performance, flexible usage, and saved hardware cost.