Abstract: The present invention relates to a security method for a smart phone, in which method a security keyboard app is installed in a smart phone of a staff member so as to make it possible to monitor information leakage. The security method for a smart phone comprises the steps of: running a first app on a smart phone and, when the first app is subject to key input, determining, by means of a security keyboard app installed in the smart phone, whether the first app is a predetermined app which is to be subject to security; monitoring the key input which is inputted to the first app, if the first app is a predetermined app that is to be subject to security; transmitting the monitored key input to a security server; and blocking the key input if the monitored key input includes a predetermined security key word.