A method for preventing a verification flaw by controlling a session time and a session data traffic is applied to a networking equipment that stores a list of verified terminal devices, a temporary permit list, and a walled garden. When a terminal device is connected to the networking equipment, the networking equipment records the media information of the terminal device on the temporary permit list and starts recording a session time and session data traffic of the terminal device. Once the session time or session data traffic exceeds its upper limit (e.g., 10 minutes or 20 MB), the networking equipment cuts off connection with the terminal device, only when a frame received from the terminal device has a matching target address in the walled garden, the networking equipment will send the frame out therethrough. Thus, the terminal device, must be verified before it can access full network services.