The invention provides a miniature three-way valve which is used for a titrator during electrochemical analysis and mainly comprises a valve, a valve element, a pressure spring and a pressure cover. The valve is cylindrical, the top of the valve is sealed, a cone is arranged at the upper end of the valve element, and a cylinder is arranged at the lower end of the valve element. Three ports are formed in the valve, and an arc-shaped groove for switching the ports is formed in the cone of the valve element. The valve and the valve elements are made of corrosion-resistant PCTFE (polychloro trifluoroethylene) and PTFE (polytetrafluoroethylene) materials by means of precision machining. The miniature three-way valve has the advantages that the miniature three-way valve is corrosion-resistant and light and is good in sealing performance, high in reliability and compact in structure; the miniature three-way valve does not need to be cleaned after being used for a long time, leakage can be prevented when the ambient temperature changes, and the requirement of the titrator on high precision can be completely met.