A reformed sulfur solidified substance producing system of the present invention includes a reformed sulfur producing tank 3 which receives and mixes molten sulfur from a molten sulfur tank 1 and sulfur reforming agent from a sulfur reforming agent tank 2 to thereby produce reformed sulfur, and at the same time, which heats the inside accommodated substance to a predetermined temperature or higher, a reformed sulfur intermediate material tank 5 which receives and mixes reformed sulfur from the reformed sulfur producing tank 3 and a fine aggregate from a fine aggregate hot bin 4 to thereby produce reformed sulfur intermediate material, and at the same time, which heats an inside accommodated substance to a predetermined temperature or higher, a mulling device 7 which receives and mulls reformed sulfur intermediate material from the reformed sulfur intermediate material tank 5 and a coarse aggregate from a coarse aggregate hot bin 6, and further, heats an inside mulled substance to a predetermined temperature or higher, and a pouring device 8 which receives and stores the raw material mulled by the mulling device 7 and heats the same to a predetermined temperature or higher, and further, measures the inside raw material and pours the same into a mold form 36. With this, it is possible to produce a reformed sulfur solidified substance which can be handled as a non-dangerous substance (here, the non-dangerous substance is a substance which does not have ignitability or an incombustible substance), and which can be easily transferred.