In this study, two phages, P69 and KYD2, were isolated from a water sample of the fishing ground. The host of P69 was Nocardia transvalensis, whereas the host of KYD2 was Nocardia carnea. Physiological characteristics and bioinformatics analysis of the isolated phages were performed. The SBR tank was simulated in the laboratory and N. carnea was added for aeration foaming. The feasibility of using phages to control sludge foaming was assessed by measuring turbidity and other water quality indices before and after adding phages and monitoring the changes in the number of hosts and phages in the device by qPCR and other technologies. Using multiple water quality indicators, qPCR, ecological community and other data to prove that P69 has a certain ability to control the sludge foaming event caused by the over-proliferation of N. carnea in the environment. It provides a novel and relatively economical solution for controlling sludge foaming in sewage treatment plants in the future.