A software installation method performed at a server, comprising: when a user requests to back up software, receiving user information and identification info of the software sent from a first mobile terminal; and establishing a corresponding relationship between the user information and the identification info of the software at the server; when the user requests to install the software that has been backed up at the server onto a second mobile terminal, receiving the information of the user and the identification info of the software sent from the second mobile terminal; and looking up corresponding relationships between user information and software information established in advance, and judging whether the corresponding relationships include the information of the user and the identification info of the corresponding software; if yes, confirming that the user has backed up the software information, looking up an installation package corresponding to the identification info of the software, and sending the installation package found to the second mobile terminal for installation of the software; wherein receiving the information of the user and the identification info of the software sent from the second mobile terminal further comprises: receiving personalized information of the user and information of an operating system of the second mobile terminal sent from the second mobile terminal, wherein the personalized information of the user is set by the user on whether to accept an installation package recommended by the server when there is no installation package matching the operating system of the second mobile terminal; and looking up an installation package corresponding to the identification info of the software comprises: according to the personalized information of the user and the information of the operating system of the second mobile terminal, judging whether the user chooses to accept a recommended installation package when there is no installation package matching the operating system of the second mobile terminal; if yes, looking up an installation package of other software relating to the software that matches the operating system of the second mobile terminal; otherwise, prompting no installation package of the software matching the operating system of the second mobile terminal. when a user requests to back up software, receiving user information and identification info of the software sent from a first mobile terminal; and establishing a corresponding relationship between the user information and the identification info of the software at the server; when the user requests to install the software that has been backed up at the server onto a second mobile terminal, receiving the information of the user and the identification info of the software sent from the second mobile terminal; and looking up corresponding relationships between user information and software information established in advance, and judging whether the corresponding relationships include the information of the user and the identification info of the corresponding software; if yes, confirming that the user has backed up the software information, looking up an installation package corresponding to the identification info of the software, and sending the installation package found to the second mobile terminal for installation of the software; wherein receiving the information of the user and the identification info of the software sent from the second mobile terminal further comprises: receiving personalized information of the user and information of an operating system of the second mobile terminal sent from the second mobile terminal, wherein the personalized information of the user is set by the user on whether to accept an installation package recommended by the server when there is no installation package matching the operating system of the second mobile terminal; and looking up an installation package corresponding to the identification info of the software comprises: according to the personalized information of the user and the information of the operating system of the second mobile terminal, judging whether the user chooses to accept a recommended installation package when there is no installation package matching the operating system of the second mobile terminal; if yes, looking up an installation package of other software relating to the software that matches the operating system of the second mobile terminal; otherwise, prompting no installation package of the software matching the operating system of the second mobile terminal. according to the personalized information of the user and the information of the operating system of the second mobile terminal, judging whether the user chooses to accept a recommended installation package when there is no installation package matching the operating system of the second mobile terminal; if yes, looking up an installation package of other software relating to the software that matches the operating system of the second mobile terminal; otherwise, prompting no installation package of the software matching the operating system of the second mobile terminal.