As a sort of convenient and efficient information tool, the computer has been widely used in various sectors of society. How to effectively prevent computer information leakage, it is an important problem facing our society today. To master the basic knowledge of computer information security, maintain computer information security and prevent computer information leakage are necessary knowledge and skills for a computer user. When processing files (documents), surfing the internet and storing files (documents), an ordinary computer user pays attention to the computer information security problem, strengthens the conscious of computer information security and takes appropriate operation skills, he(or she ) will be able to effectively prevent the leakage of computer information, reduce the risk of information security, and avoid unnecessary losses or adverse effect.