The utility model discloses a liquid separate-charging device which comprises a gas diaphragm, a first positive pressure pump, a second positive pressure pump, a negative pressure pump, a first three-way valve, a second three-way valve and a seal bottle; the gas diaphragm is respectively communicated with inlets of the first positive pressure pump and the second positive pressure pump; two communication ports in the first three-way valve are respectively communicated with an outlet of the first positive pressure pump and an inlet of the negative pressure pump; the seal bottle is simultaneously communicated with a liquid source, the other communication port of the first three-way valve and a communication port of the second three-way valve; and the other communication port of the second three-way valve is communicated with an outlet of the second positive pressure pump. The liquid separate-charging device carries out separate charging under the seal state, is safe and reliable, and prevents workers from the danger of radiation.