The invention discloses a production device for sulfur based compound fertilizer with high content of water-soluble phosphorus. The production device comprises a mother liquor storage tank and a diluted phosphoric acid storage tank, wherein both the mother liquor storage tank and the diluted phosphoric acid storage tank are connected to a conversion bath, a discharging port of the conversion bath is connected with a tubular reactor, a flash evaporation unit and a spraying granulation drier sequentially; the flash evaporation unit is connected with a scrubber, the spraying granulation drier is connected with a Venturi scrubbing tower, and both the scrubber and the Venturi scrubbing tower are connected to an exhausting chimney. The content of water-soluble phosphorus in the sulfur based compound fertilizer produced by the device is higher than that of water-soluble phosphorus in the conventional sulfur based compound fertilizer by 5% or higher mainly by means of the high content of water-soluble phosphorus in industrial monoammonium phosphate mother liquor stored in the mother liquor storage tank; the compound fertilizer with more mellow and fuller appearance and more uniform granularity can be obtained, the production device for the sulfur based compound fertilizer is easy to operate during granulation, production control is more stable, and the capacity of the device can be exerted to the greatest extent.