The utility model discloses a mouse fixing device for experiments. The device comprises a fixing plate, a fixing unit and a label unit are arranged on the fixing plate; The fixing unit comprises fourfirst fixing assemblies used for fixing the four limbs of a mouse. the second fixing assembly is used for fixing the head of the mouse; Each first fixing assembly comprises a positioning plate movingin the X-axis direction. the pull rod is arranged on the positioning plate and can move in the Y-axis direction relative to the positioning plate; wherein the two ends of the pull rod are fixedly connected with the four limbs of the mouse respectively, a guide groove and a plurality of gear grooves used for fixing the pull rod are formed in the positioning plate, the gear grooves are formed belowthe guide groove and communicated with the guide groove, and the second fixing assembly comprises a pull hook which moves in the X direction to fix the lower jaw of the mouse. The mouse labeling device at least has the advantages that the tension degree of four limbs and the tension degree of the head can be adjusted according to the body type of a mouse, and the mouse can be labeled convenientlyand rapidly and the labeling position can be adjusted.