The invention discloses a DC signal variance adaptive detection method and a device. The method comprises the steps of conducting the adaptive smooth adjustment on reference signals and conducting the negative-feedback intervention and adjustment on output signals. Firstly, an original DC signal is tracked in real time to generate a reference signal in combination with the algorithm. After that, the reference signal and the original signal are subjected to differential amplification, and then an output signal is led in for adaptive feedback adjustment. In this way, the problem in the prior art that the correctness and the precision of the DC signal variance detection are influenced by environmental factors and human factors can be solved. The precise output of multiple-type and multiple-channel detection signals is enabled. The above method is suitable for original signals significantly affected by environmental factors and high in static output and small in variance.