The invention relates to a multi-function analog signal acquisition circuit. With controlling of turning on and off of a switch, whether a voltage signal outputted by the analog signal acquisition circuit reaches a peak value of a fixed limit or a normal working voltage range is determined; when the switch is turned on and the voltage signal outputted by the analog signal acquisition circuit reaches the peak value of the fixed limit, measurement of a current analog quantity is determined to be needed by the circuit; and then the switch is turned off, the circuit outputs a voltage converted from a to-be-tested current. When the voltage signal outputted by the circuit is in a normal working range, measurement of a voltage analog quantity is determined to be needed by the circuit and the circuit outputs a voltage converted from a to-be-tested voltage directly. With one analog signal acquisition circuit, monitoring of a to-be-tested current and a to-be-tested voltage can be completed without adding another signal acquisition circuit, so that the circuit design cost can be saved. Meanwhile, the circuit having a simple structure is easy to product and debug; the loop sampling precision is high and stable; and the bias voltage and temperature drift voltage are low.