The utility model discloses a micro-antigen emulsifier capable of sampling and monitoring an emulsifying state at any time and provided with a low-temperature device. The micro-antigen emulsifier comprises two injectors, a three-way valve, a sampling needle head and a combined ice box, a connector at the bottom of the injector sleeve is provided with an external thread and is hermetically connected with two ends of a three-way valve with an internal thread through screw buckles, so that the two injectors are communicated through the three-way valve; a sample outlet with external threads is formed in one end, connected with the needle head, of the three-way valve and is hermetically connected with the needle head with internal threads at the top end; the sample outlet can be sealed or opened by rotating the three-way valve, so that sampling and emulsification state monitoring at any time in the emulsification process are facilitated. The combined ice box is filled with a refrigerant andis divided into an upper part and a lower part, and a groove capable of being just matched with two injectors and a three-way valve is formed in the combined ice box to ensure low-temperature emulsification. The sampling needle head of the three-way valve can be selected according to sampling requirements. The device for emulsifying the antigen is simple, convenient and efficient, and each component can be repeatedly used after being cleaned.