The abnormal fluctuations of sulfur dioxide (SO2) and its derivatives are closely associated with various physiology and pathological progresses in biological system. Herein, we have developed two fluorescent and colorimetric probes (1 and 2) based on hemicyanine dye for the detection of SO2 derivatives and hydrogen peroxide (H2O2) in vitro and live cells. The response mechanisms involve SO2 derivatives mediated nucleophilic addition reaction to the double bond and subsequent H2O2 promoted elimination of bisulfite. Besides having excellent photophysical properties, probe 1 with higher fluorescence efficiency is further applied for live cells imaging, indicating that it can solely accumulate into mitochondria and track SO2 derivatives and H2O2 in live cells.