A method for indexing an external SD card. The method comprises: acquiring a mount path list; determining whether or not a filter criterion is satisfied by each mount path in the mount path list, if the criterion is satisfied, then splitting with spaces a current mount path into multiple paths, determining whether or not each path contains a preset string, and if yes, then recording the current path as a suspected external SD card path; and, determining whether or not a final external SD card path is in the suspected external SD card path recorded, if yes, then a final external SD card is found, and if not, then no final external SD card is found. By analyzing a file system table and a mount command, the present invention implements acquisition of a mount path of an external SD card on Android platforms of different versions and different customizations, thus allowing the implementation in an Android operating system of external SD card indexing without having to rely on an API function for implementation, and improving compatibility.