An interactive white board, comprising: a touch device, a device processor, a first control unit, and multiple first channel modules, wherein the touch device is connected to the device processor, the device processor is connected to the touch device and the first control unit, and the first control unit is connected to the device processor and the multiple first channel modules, wherein: the touch device, is configured to generate first touch data and send the first touch data to the device processor; the device processor, is configured to mark the first touch data according to a current display channel to generate second touch data and send the second touch data to the first control unit, wherein the second touch data comprises an identifier corresponding to the current display channel; the first control unit, is configured to distribute the second touch data to a corresponding one of the multiple first channel modules according to the identifier corresponding to the current display channel; and the first channel modules, is configured to receive the second touch data and and make a touch response, characterized in that the device processor is further configured to, prior to determining the identifier for marking the first touch data according to the current display channel of the interactive white board, perform the following steps: detecting whether the display channel changes, wherein the display channel changes when the interactive white board switches a channel module; if the display channel changes, detecting whether a last set of touch data before the display channel changes is in its integrity; and if the last set of touch data before the display channel changes is not in its integrity, using supplementary points to supplement an end point of the last set of touch data before the display channel changes and a start point of a first set of touch data after the display channel changes, wherein the supplementary points are first touch points after the display channel changes. the touch device, is configured to generate first touch data and send the first touch data to the device processor; the device processor, is configured to mark the first touch data according to a current display channel to generate second touch data and send the second touch data to the first control unit, wherein the second touch data comprises an identifier corresponding to the current display channel; the first control unit, is configured to distribute the second touch data to a corresponding one of the multiple first channel modules according to the identifier corresponding to the current display channel; and the first channel modules, is configured to receive the second touch data and and make a touch response, characterized in that the device processor is further configured to, prior to determining the identifier for marking the first touch data according to the current display channel of the interactive white board, perform the following steps: detecting whether the display channel changes, wherein the display channel changes when the interactive white board switches a channel module; if the display channel changes, detecting whether a last set of touch data before the display channel changes is in its integrity; and if the last set of touch data before the display channel changes is not in its integrity, using supplementary points to supplement an end point of the last set of touch data before the display channel changes and a start point of a first set of touch data after the display channel changes, wherein the supplementary points are first touch points after the display channel changes. detecting whether the display channel changes, wherein the display channel changes when the interactive white board switches a channel module; if the display channel changes, detecting whether a last set of touch data before the display channel changes is in its integrity; and if the last set of touch data before the display channel changes is not in its integrity, using supplementary points to supplement an end point of the last set of touch data before the display channel changes and a start point of a first set of touch data after the display channel changes, wherein the supplementary points are first touch points after the display channel changes.