Edge layout is an important aspect of network visualization and an essential tool for representing the overall structure of network and revealing the hidden information pattern. To survey and analyze the existing edge layout techniques, this paper first gives an overview on the tasks of edge layout of network and the aesthetics standards of graph drawing. Then, it classifieds the edge layout techniques into three categories. Edge routing (ER), edge confluent (EC), and edge bundling (EB). Next, it elaborates the principles and characteristics of the typical layout methods, and highlights the analytics of edge bundling technique. Finally, this paper reviews the existing open problems, and offers an outlook on future work and challenges of edge layout.