Multi-stage steam using system for polycrystalline silicon production

The utility model relates to a multi-stage steam using system for polycrystalline silicon production, which is characterized in that the outlets of a first condensate tank and a second condensate tank are connected with the inlet of a blow-down tank, the blow-down tank is provided with a nitrogen pressurizing pipeline, and the first condensate tank and the second condensate tank are provided with conductivity detection probes; the detection device, the first valve, the second valve, the third valve, the fourth valve, the fifth valve and the sixth valve are all electrically connected with the control device. According to the steam circulating system, water changing and pollution discharging operations of a plurality of steam circulating systems can be automatically completed, each steam circulating system only needs to be provided with one condensate tank, large construction cost of the steam circulating systems is avoided, and water changing and pollution discharging operations of the whole steam circulating