The disclosed watchdog control method includes processes: (1) according to interruption time interval, the system generates interrupt, which triggers interrupt service routine; (2) reading out time variable; the time variable adds an interruption time interval when each interrupt takes place in the system; (3) comparing value of time variable with maximal time interval for feeding dog setup in system; when value of time variable is not larger than maximal time interval for feeding dog, the interrupt service routine feeds dog; when value of time variable is larger than maximal time interval, the interrupt service routine stops feeding dog, and the watchdog module resets system; (4) when application program feeds dog, the value of time variable is reset. Since maximal time interval for feeding dog can be set based on condition, longer time interval is allowed so as to prevent issue of resetting system caused by feeding dog not in time since application program for feeding dog is blocked.