1. A method of acquiring multimedia data, applied in a multimedia data acquisition apparatus, the multimedia data acquisition apparatus comprising a multimedia sensor, a triggering device, and a buffer memory, the method comprising: performing a data pre-acquisition process by acquiring multimedia data by the multimedia sensor before the triggering device is activated; storing the multimedia data acquired by the multimedia sensor in performing the data pre-acquisition process in the buffer memory; terminating the data pre-acquisition process when the triggering device is activated; displaying at least a set of the multimedia data stored in the buffer memory for a user to select; deleting the multimedia data previously displayed but not selected by the user; and displaying both the set of multimedia data previously selected by the user and the multimedia data that are stored in the buffer memory but not displayed previously in order to further provide the user with a set of selections after the displayed-but-not-selected multimedia data are deleted.