The present application belongs to the technical field of excitation rod temperature reduction design in the vibration mode test, and particularly relates to a cooling device for reducing the excitation rod temperature in the thermal mode test. The device comprises: a pillar; a large arm, wherein one end of the large arm is connected with the pillar, the end is called a large arm connecting end, and the large arm can move axially along the pillar and can rotate around the pillar; a small arm, wherein one end of the small arm is connected with the large arm, the end is called a small arm connecting end, and the small arm can move axially along the large arm and can rotate around the large arm; and a wind head. A hollow air cavity is formed in the wind head, and an air inlet hole is opened on the wind head; one end of the air inlet hole is communicated with the air cavity, and the other end is used to communicate with a cooling gas source; the wind head has an air outlet surface, a plurality of air outlet holes are opened on the wind head, one end of each air outlet hole is connected with the air cavity, and the other end extends to the air outlet surface; and the wind head is connected with the small arm, can move axially along the small arm, and can rotate around the small arm.