A method for improving security level of a terminal when the terminal surfs the Internet, comprising: receiving, by a network side, characteristic code information of a file reported by a terminal, wherein the characteristic code information of the file is collected by the terminal using a first collecting algorithm, comparing, by the network side, the characteristic code information reported by the terminal with a characteristic code of a safe file, and comparing the characteristic code information reported by the terminal with a characteristic code of an unsafe file, wherein if the characteristic code information of the file matches both the characteristic code of the safe file and the characteristic code of the unsafe file, the compared results conflict with each other; and if the compared results conflict with each other, transmitting an indication to the terminal indicating the terminal to collect the characteristic code information of the file again until the compared results do not conflict, wherein the indication transmitted by the network side to the terminal indicates a second collecting algorithm, wherein the terminal collects the characteristic code information of the file using the second collecting algorithm indicated by the network side, wherein the terminal collects the characteristic code of a plurality of first parts of the file according to the first collecting algorithm and collects the characteristic code of a plurality of second parts of the file according to the second collecting algorithm, the first parts are different from the second parts, and the first collecting algorithm is different from the second collecting algorithm; otherwise, generating a network security policy according to the characteristic code information reported by each terminal, and transmitting a security indication according to the network security policy to the terminal; and providing, by the terminal, a security prompt for network information to be obtained or having been obtained according to the security indication; wherein the security indication comprises a black list and/or a white list of network security information; and the providing the security prompt for the network information to be obtained or having been obtained comprises: when a user inputs a website address in a browser, obtaining, by the terminal, locally-stored relevant addresses through a fuzzy match according to the website address input by the user, comparing the relevant addresses with addresses in the black list and/or the white list, and displaying the security prompt according to a compared result. receiving, by a network side, characteristic code information of a file reported by a terminal, wherein the characteristic code information of the file is collected by the terminal using a first collecting algorithm, comparing, by the network side, the characteristic code information reported by the terminal with a characteristic code of a safe file, and comparing the characteristic code information reported by the terminal with a characteristic code of an unsafe file, wherein if the characteristic code information of the file matches both the characteristic code of the safe file and the characteristic code of the unsafe file, the compared results conflict with each other; and if the compared results conflict with each other, transmitting an indication to the terminal indicating the terminal to collect the characteristic code information of the file again until the compared results do not conflict, wherein the indication transmitted by the network side to the terminal indicates a second collecting algorithm, wherein the terminal collects the characteristic code information of the file using the second collecting algorithm indicated by the network side, wherein the terminal collects the characteristic code of a plurality of first parts of the file according to the first collecting algorithm and collects the characteristic code of a plurality of second parts of the file according to the second collecting algorithm, the first parts are different from the second parts, and the first collecting algorithm is different from the second collecting algorithm; otherwise, generating a network security policy according to the characteristic code information reported by each terminal, and transmitting a security indication according to the network security policy to the terminal; and providing, by the terminal, a security prompt for network information to be obtained or having been obtained according to the security indication; wherein the security indication comprises a black list and/or a white list of network security information; and the providing the security prompt for the network information to be obtained or having been obtained comprises: when a user inputs a website address in a browser, obtaining, by the terminal, locally-stored relevant addresses through a fuzzy match according to the website address input by the user, comparing the relevant addresses with addresses in the black list and/or the white list, and displaying the security prompt according to a compared result.