For tumor resection, the key step is to distinguish normal from tumor cells accurately. In this article, a lysosome targeting double site fluorescent probe T was reported for porcine pancreatic lipase (PPL) and hydrogen sulfide (H 2 S). In PBS solution, T could be hydrolyzed by PPL and emitted yellow fluorescence, but no fluorescence change could be observed by H 2 S only. While in the coexistence of PPL and H 2 S, a double site chemical reaction was activated, and blue fluorescence was found in the end. The concentration of H 2 S in some cancer cells is high enough to trigger this dual-site chemical reaction for T. This phenomenon can be repeated in cell experiments: T emits yellow fluorescence in normal cells (MPC) and blue fluorescence in cancer cells (HeLa and SMCC-7721). It illuminates a fact that a vast amount of H 2 S existed in these cancer cells. As a result, probe T could be used to distinguish cancer cells from normal cells with different fluorescence colors. • A lysosome targeting double site fluorescent probe T for lipase and H 2 S. • Distinguish normal cells from tumor cells. • T emits yellow fluorescence in normal cells but blue in cancer cells. [ABSTRACT FROM AUTHOR]