This paper introduces a 100 MPa water gas two-phase fluid pressurization device.The device can provide 100 MPa gas pressure and 200 MPa liquid pressure for small volume(＜ 20 mL)high-pressure experimental devices.This device can make the pressure control inde-pendent of the temperature control without changing the material components of the system.The resolution of this device in adjusting the pressure is ± 0.2 MPa in the pro-cess of boosting and depressurizing.This pressure boosting device generates very little vibration during work and it can be used in experiments with strict requirements on vibra-tion.As a thermodynamic parameter,pressure has a great influence on matter.In the field of experimental geo-chemistry,pressure is not only an experimental method and an extreme condition but an important physical parameter independent of temperature and chemical composition.