Reactive sulfur species have received considerable attention due to their various biological functions. Among these molecules, hydrogen polysulfides (H2Sn, n > 1) are recently suggested to be the actual signaling molecules derived from hydrogen sulfide (H2S). Hydrogen polysulfides may also have their own biosynthetic pathways. The research on H2Sn is rapidly growing. However, the detection of H2Sn is still challenging. In this work we report a H2Sn-mediated benzodithiolone formation under mild conditions. Based on this reaction, specific fluorescent probes for H2Sn are prepared and evaluated. The probe DSP-3 shows good selectivity and sensitivity for H2Sn.