A user interface switching method, suitable for a portable electronic device having a touch screen (300, 910), the method comprising: providing a plurality of user interfaces (310, 510, 530, 710, 730, 810, 830), and displaying one of the user interfaces (310, 510, 530, 710, 730, 810, 830) in the touch screen (300, 910); characterized in that the method further comprises the steps of: displaying a representative icon bar and a hot key bar (320, 340, 720, 740) in the touch screen (300, 910), wherein the representative icon bar comprises a plurality of representative icons (210, 220, 230, 240, 250, 260, 270, 280, 290) respectively corresponding to the user interfaces (310, 510, 530, 710, 730, 810, 830), and the hot key bar (320, 340, 720, 740) comprises one or multiple hot keys corresponding to the currently displayed user interface (310, 510, 530, 710, 730, 810, 830); detecting a touch signal by the touch screen (300, 910); in response to the touch signal being detected to fall in one representative icon (210, 220, 230, 240, 250, 260, 270, 280, 290) in the representative icon bar but not to be moved within the representative icon bar, switching to the user interface (310, 510, 530, 710, 730, 810, 830) and the hot key bar (320, 340, 720, 740) corresponding to the representative icon (210, 220, 230, 240, 250, 260, 270, 280, 290) which the touch signal fell in and terminated; and in response to the touch signal being detected to fall in the user interface (310, 510, 530, 710, 730, 810, 830) and be moved in a sliding manner within the user interface (310, 510, 530, 710, 730, 810, 830) and a displacement of sliding of the touch signal exceeds a predetermined value, then switching the user interface (310, 510, 530, 710, 730, 810, 830) to the next one user interface or to the previous one user interface in response to the moving direction of the touch signal, and switching the hot key bar (320, 340, 720, 740) corresponding to the switched user interface (310, 510, 530, 710, 730, 810, 830). providing a plurality of user interfaces (310, 510, 530, 710, 730, 810, 830), and displaying one of the user interfaces (310, 510, 530, 710, 730, 810, 830) in the touch screen (300, 910); characterized in that the method further comprises the steps of: displaying a representative icon bar and a hot key bar (320, 340, 720, 740) in the touch screen (300, 910), wherein the representative icon bar comprises a plurality of representative icons (210, 220, 230, 240, 250, 260, 270, 280, 290) respectively corresponding to the user interfaces (310, 510, 530, 710, 730, 810, 830), and the hot key bar (320, 340, 720, 740) comprises one or multiple hot keys corresponding to the currently displayed user interface (310, 510, 530, 710, 730, 810, 830); detecting a touch signal by the touch screen (300, 910); in response to the touch signal being detected to fall in one representative icon (210, 220, 230, 240, 250, 260, 270, 280, 290) in the representative icon bar but not to be moved within the representative icon bar, switching to the user interface (310, 510, 530, 710, 730, 810, 830) and the hot key bar (320, 340, 720, 740) corresponding to the representative icon (210, 220, 230, 240, 250, 260, 270, 280, 290) which the touch signal fell in and terminated; and in response to the touch signal being detected to fall in the user interface (310, 510, 530, 710, 730, 810, 830) and be moved in a sliding manner within the user interface (310, 510, 530, 710, 730, 810, 830) and a displacement of sliding of the touch signal exceeds a predetermined value, then switching the user interface (310, 510, 530, 710, 730, 810, 830) to the next one user interface or to the previous one user interface in response to the moving direction of the touch signal, and switching the hot key bar (320, 340, 720, 740) corresponding to the switched user interface (310, 510, 530, 710, 730, 810, 830). displaying a representative icon bar and a hot key bar (320, 340, 720, 740) in the touch screen (300, 910), wherein the representative icon bar comprises a plurality of representative icons (210, 220, 230, 240, 250, 260, 270, 280, 290) respectively corresponding to the user interfaces (310, 510, 530, 710, 730, 810, 830), and the hot key bar (320, 340, 720, 740) comprises one or multiple hot keys corresponding to the currently displayed user interface (310, 510, 530, 710, 730, 810, 830); detecting a touch signal by the touch screen (300, 910); in response to the touch signal being detected to fall in one representative icon (210, 220, 230, 240, 250, 260, 270, 280, 290) in the representative icon bar but not to be moved within the representative icon bar, switching to the user interface (310, 510, 530, 710, 730, 810, 830) and the hot key bar (320, 340, 720, 740) corresponding to the representative icon (210, 220, 230, 240, 250, 260, 270, 280, 290) which the touch signal fell in and terminated; and in response to the touch signal being detected to fall in the user interface (310, 510, 530, 710, 730, 810, 830) and be moved in a sliding manner within the user interface (310, 510, 530, 710, 730, 810, 830) and a displacement of sliding of the touch signal exceeds a predetermined value, then switching the user interface (310, 510, 530, 710, 730, 810, 830) to the next one user interface or to the previous one user interface in response to the moving direction of the touch signal, and switching the hot key bar (320, 340, 720, 740) corresponding to the switched user interface (310, 510, 530, 710, 730, 810, 830).