The network robustness against cascades is crucial for many networked systems. In the paper, we enhance the network robustness against cascades by rewiring edges of networks. Three edge-rewiring strategies are compared, including random rewiring strategy (RRS), assortative rewiring strategy (ARS), and low-polarization rewiring strategy (LPRS). The results show that ARS is more effective than RRS to improve the network robustness against cascades while the network achieves the strongest robustness level under LPRS. We also investigate the effects of the total cost of edge-rewiring. It is found that the superiority of LPRS becomes more evident than ARS and RRS as the total cost grows. Our work might shed light on the design of networked systems.