The invention discloses a probiotic fermented drink preparation system, which comprises a stock solution preparation drum, a potable water storage unit, an aeration fermentation tank and a finished product receiving container. A water outlet end of the potable water storage unit is connected with a water inlet end of the stock solution preparation drum through a water guide pipe. A raw material feeding pipe is arranged on the upper side of one end of the stock solution preparation drum in a communicated manner and provided with a feeding hopper. A stock solution discharging end of the stock solution preparation drum is connected with a feeding end of the top of the aeration fermentation tank through the feeding pipe. The system is simple in structure, and potable water and raw materials are quickly and uniformly mixed through continuous stirring of screw blades to further form fermentation stock solution; meanwhile, a second electromagnetic liquid valve is turned on, a liquid pump is started, then fermentation stock solution mixed in a stock solution mixing passage is continuously pumped into the aeration fermentation tank by the liquid pump, and stock solution entering the aeration fermentation tank is basically uniform liquid.