In order to improve the accuracy of the angle of attack mechanism of the wind tunnel, the angle of attack mechanism of the 4 m × 3 m low speed wind tunnel was modified by using a worm gear pair based on the split worm technology. The principle and realization of the split worm technology are analyzed, and the static and dynamic tests of the modified angle of attack mechanism are carried out. The results show that the positioning accuracy of the angle of attack and the quality of the test data are improved by using the angle of attack mechanism with split worm technology, which lays a good foundation for the follow-up test of the wind tunnel.