The full tooth dynamic finite element model of the GIICL9 crown gear coupling is established based on the ANSYS/LS-DYNA.The research results demonstrate that,the impact phenomenon need to be controlled in the start-up process,and the contact stress distribution along the high direction of the tooth is not uniform.In addition,the average contact stress value of each tooth is also different.The smaller of the tool displacement circle radius,the more discrete the contact stress of each tooth.The maximum mises stress of tooth root and contact stress tooth surfaces will not be affected by the rotational speed as the running process is stable.