The invention relates to a universal data acquisition unit and a data acquisition method thereof, belonging to the technical field of data acquisition; the universal data acquisition unit comprises amicroprocessor; a multi-path discrete signal input interface is connected with the input end of a counter by a photoelectric isolating circuit, and a multi-path continuous signal input interface is connected with the input end of an A/D converter, and a microprocessor is connected with the input ends of the A/D converter and the counter. The data acquisition method comprises that: system initialization is carried out; continuous and discrete signal interrupt vector is set; interrupt latency is carried out, if the discrete signal is interrupted, the discrete signal is acquired; if the continuous signal is interrupted, the continuous signal is acquired; if a watchdog is interrupted, a system is restarted; if hibernation is interrupted, system setting data is stored, and then a hibernation state is carried out; and then, interrupt latency awaken operation is carried out, if awakening is interrupted, the system is started, and the setting is restored before interruption; if the continuoussignal and the discrete signal are acquired, interrupt latency is continuously carried out after data is transmitted to an upper computer; if not, interrupt latency is carried out directly.