The invention discloses a method for an online secure logging-on, comprises steps of: determining a correlation between at least one of processes and a logging-on operation; sorting the at least one of processes to two classes, that is, processes related to the logging-on operation and processes unrelated to the logging-on operation; running at least one of the processes related to the logging-on operation, when the logging-on operation is performed and a number of the processes related to the logging-on operation is one or more; and suspending at least one of the 1o processes unrelated to the logging-on operation, when the logging-on operation is performed and a number of the processes unrelated to the logging-on operation is one or more. The scheme of the present invention utilizes a real-time protection, needs less monitoring on the operating system and is easy to guarantee the stability. Since most processes of the operating system are suspended, the protection is more reliable. Corresponding to the method, the present invention also provides a device for an online secure logging-on.