Abstract: China North Nuclear Fuel Co. Ltd（CNNC） built a HTGR nuclear fuel element production line. In this production line, the gel ball is mainly prepared by external gelation of uranium process（EGU）. In the engineering research process, the problems such as the paste liquid deposition and the gel liquid flow can not be controlled accurately during Sol-gel, and gel ball cracks occur. In order to solve these engineering problems, the gel ball preparation process and equipment were optimized and modified, and 10 batches of UO₂ kernels were tested and verified. The results show that the improved production line can achieve continuous and stable industrial production, and the qualified UO₂ kernel products are over 80%.