The invention provides a coagulant preparing and feeding system. The system includes a coagulant dissolution stirring tank, a coagulant storage tank and a coagulant delivery measuring pump; the coagulant dissolution stirring tank is provided with a stirring device; the stirring device of the coagulant dissolution stirring tank includes a second stirring motor, a second stirring shaft and a secondmixing blade, the coagulant storage tank includes a tank body and two heating and stirring devices respectively disposed on both sides of the coagulant storage tank, and each heating and stirring device includes a first stirring motor, a first stirring shaft and a first stirring blade, a heating resistance wire and a metal outer shell; according to the system, the heating and stirring devices in the coagulant storage tank are mainly used for avoiding the crystallization agglomeration phenomenon of coagulants and for ensuring the fluency of coagulant preparing and feeding equipment.