The transmission shaft connecting CH and CV in GDX2 packer always breaks down due to attrition. Its integrated design and small repair space make it time-and-energy consuming to replace the damaged transmission shaft, which inspires us to improve itsuniversal joints. Based on its original transmission principle, we substitute the fast respectively demountable units for the transmission gear, which made the installment more efficient. While repairing, only the broken units needed to be beplaced. The application result showed that the improved universal joints function reliably, with less labors, and greatly increased the effective operation rate because of its simple structure.