In view of the shortage of calculation methods for anchor chain design in the existing water transport codes and manuals，this paper performs theoretical derivation and proposes numerical solution methods.By catenary theory derivation，the paper obtains the basic curve equation of the drag form of the anchor chain and lists the supplementary equations for anchor chains not dragging the ground and anchor chains with a settlement in the middle.The results show that this method can be combined with mathematical software to accurately solve the curve equation，anchor angle，anchor distance，anchor tension，and other parameters under various working conditions，such as anchor chain dragging，no dragging，and settlement in the middle.