研究Sweedler 4-维Hopf代数H4 Drinfeld偶D(H4)的Grothendieck环G0(D(H4))的自同构群,给出了G0(D(H4))所有环自同构的表达式,并证明了Grothendieck环G0(D(H4))的自同构群同构于Klein群K4.