The invention discloses a fast liquid-injection system. The fast liquid-injection system comprises a liquid storage tank, a power transfer device, a reactor, a first three-way valve and a second three-way valve; the power transfer device comprises a power device and a transfer container which are connected; the power device is used for providing power for the transfer container, and the transfer container is used for liquid transfer and provided with an injecting opening and a liquid discharging opening; and the injecting opening is connected with the first three-way valve, the liquid discharging opening is connected with the second three-way valve, and the first three-way valve and the second three-way valve are further connected with the liquid storage tank and the reactor correspondingly. According to the fast liquid-injection system, liquid injection and suction control can be completed at a time, the tedious experimental process is reduced, the experimental efficiency is improved,meanwhile, the liquid injection process can be conducted continuously, the intermittent liquid injection phenomenon can be avoided, and the accuracy of an experiment is ensured; and in addition, theliquid injection amount can further be effectively controlled, and thus the experimental purpose is achieved.