The evolution of Jingjiang River-Dongting Lake connection and the interference of human activities lead to the degradation of water network in flood storage polders of the Dongting Lake area, resulting in the weakened ability of agricultural irrigation and flood drainage of the farmland ditch network. Based on the theory of landscape ecology, this study quantitatively evaluated the connectivity of the current water network in 20 flood storage polders using the evaluation indices of water network connectivity, including the river network density, the circle degree of water network, the node connection rate and the network connectivity. The results show that the overall river network density, the node connection rate and the network connectivity are high in these 20 polders, whereas the circle degree of water network is relatively low. The 20 polders were classified into three types, different optimization strategies for their water network connection were proposed accordingly and then implemented to the Qianlianghu, Quyuan and Anli flood storage polders. After the implementation of individual optimization strategies, the river network density of the three polders increased by 5.09%, 7.32% and 10.63%, the circle degree of water network increased by 0.66%, 16.67% and 4.55%, the node connection rate increased by 0.25%, 3.99% and 2.16%, the network connectivity increased by 0.19%, 4.35% and 2.08%, respectively. This study can provide some reference for the management of ditch network connection projects in flood storage polders of plain lake area, and the improvement of agricultural irrigation and flood control capacity.