A virtual online conference system, comprising: an end-user application, installed in and executed on an end-user apparatus; and a server wirelessly connected with the end-user apparatus and configured to receive multiple audiovisual data from multiple external audiovisual devices and transmit the multiple audiovisual data to the end-user apparatus under a streaming approach; wherein the end-user application comprises: an audiovisual streaming module, configured to receive the multiple audiovisual data provided from the server; a first device inquiring module, configured to request the server for device information of the multiple external audiovisual devices; a setting module, configured to control the first device inquiring module and the audiovisual streaming module to communicate with the server and to create and to control multiple virtual interfaces based on the device information, wherein each of the multiple virtual interfaces corresponds to one of the multiple external audiovisual devices; and an audiovisual synthesis module, configured to synthesize the multiple audiovisual data to be received; wherein the end-user application is configured to create the multiple virtual interfaces correspondingly based on the device information of the multiple external audiovisual devices connected with the server through the setting module, such that the multiple audiovisual data are changed from internal audiovisual devices of the end-user apparatus to the multiple external audiovisual devices connected with the server corresponding to the multiple virtual interfaces selected, wherein the audiovisual synthesis module is configured to synthesize the multiple audiovisual data based on a corresponding timestamp of the multiple audiovisual data such that the multiple audiovisual data are synchronized, and the end-user apparatus is configured to provide the multiple audiovisual data through the multiple virtual interfaces to be an input data of an online conference software, such that the end-user apparatus executes the online conference software by using the multiple audiovisual data of the multiple external audiovisual devices obtained from the server as the input data of the online conference software to attend the online conference. an end-user application, installed in and executed on an end-user apparatus; and a server wirelessly connected with the end-user apparatus and configured to receive multiple audiovisual data from multiple external audiovisual devices and transmit the multiple audiovisual data to the end-user apparatus under a streaming approach; wherein the end-user application comprises: an audiovisual streaming module, configured to receive the multiple audiovisual data provided from the server; a first device inquiring module, configured to request the server for device information of the multiple external audiovisual devices; a setting module, configured to control the first device inquiring module and the audiovisual streaming module to communicate with the server and to create and to control multiple virtual interfaces based on the device information, wherein each of the multiple virtual interfaces corresponds to one of the multiple external audiovisual devices; and an audiovisual synthesis module, configured to synthesize the multiple audiovisual data to be received; an audiovisual streaming module, configured to receive the multiple audiovisual data provided from the server; a first device inquiring module, configured to request the server for device information of the multiple external audiovisual devices; a setting module, configured to control the first device inquiring module and the audiovisual streaming module to communicate with the server and to create and to control multiple virtual interfaces based on the device information, wherein each of the multiple virtual interfaces corresponds to one of the multiple external audiovisual devices; and an audiovisual synthesis module, configured to synthesize the multiple audiovisual data to be received; wherein the end-user application is configured to create the multiple virtual interfaces correspondingly based on the device information of the multiple external audiovisual devices connected with the server through the setting module, such that the multiple audiovisual data are changed from internal audiovisual devices of the end-user apparatus to the multiple external audiovisual devices connected with the server corresponding to the multiple virtual interfaces selected, wherein the audiovisual synthesis module is configured to synthesize the multiple audiovisual data based on a corresponding timestamp of the multiple audiovisual data such that the multiple audiovisual data are synchronized, and the end-user apparatus is configured to provide the multiple audiovisual data through the multiple virtual interfaces to be an input data of an online conference software, such that the end-user apparatus executes the online conference software by using the multiple audiovisual data of the multiple external audiovisual devices obtained from the server as the input data of the online conference software to attend the online conference.