The present application provides methods and systems for limiting data traffic. According to some embodiments, one exemplary method includes: determining, at an application layer, one or more parent process objects corresponding to a service object; creating at least one corresponding child process object by using the parent process objects respectively, and allocating a maximum input/output (I/O) bandwidth threshold for the child process object and prompting, when it is detected that the child process object inputs or outputs a network data packet, an operating system kernel layer to limit data traffic of the network data packet according to the maximum I/O bandwidth threshold. Embodiments of the present application can improve the stability of network isolation.