A dual-system-based data storage method, comprising the steps of (S301) judging whether the data is important data when storing data in a first system; and (S302) storing the data into a second system if it is judged that the data is important data. Thus, in a dual-system environment, the important data handled by a user in a first system can be quickly and conveniently stored into a second system, thereby sufficiently protecting information security for the user.