The repair and reconstruction of long ureteral defects is a technical challenge faced by urologists. The ileal ureter replacement is currently the main surgical method for treating long segment ureteral defects. After the ileal ureter replacement surgery, mucin 2 (MUC2) and mucin 3 (MUC3), which are the main functional components of ileal mucus, continue to be strongly expressed. In addition, the expression of MUC2 gene after surgery is not limited to goblet cells, but can even be expressed in absorption cells of the ileum, ultimately leading to a large amount of mucin synthesis and mucus secretion. Mucus can cause many complications such as obstruction and infection, seriously affecting the treatment effect. At present, the industry has tried various methods to reduce the secretion of mucus and related complications after ileal ureteral replacement surgery, such as cutting the ileum to reduce mucosal area and mucosal exfoliation to reduce mucus production, and has achieved certain results. This article provides a review of research progress on the types, molecular mechanisms, and solutions of mucus related complications after ileal ureteral replacement surgery.