The utility model relates to a data acquisition system. The system comprises: a controller which comprises an analog-digital conversion port, a first address selection port, and a second address selection port; multi-channel analog switches, each of which comprises channel selection ports in connection with the second address selection port of the controller, analog signal output ports in electrical connection with the analog-digital conversion port, an enabling port, and a plurality of groups of analog signal input ports; and a decoding selection circuit which comprises an input terminal connected with the first address selection port of the controller, and an output terminal connected with the enabling port of the multi-channel analog switch. The system provided can use channels of a plurality of multi-channel analog switches as detection channels by means of the controller, and can operate on a number of detection channels at the same time. The system is characterized by a simple structure, easy operation and low costs.