A method of communication between a touch control device with a touch screen and an external device, comprising the following steps: when the external device communicates with the touch control device, sending, by the external device, 1-bit data to the touch screen within each sending period, wherein the 1-bit data sent within each sending period is a combination of a valid signal and an invalid signal, or an invalid signal; scanning, by the touch control device, the 1-bit data based on a predetermined scanning period to obtain N frames of scanned data, wherein the predetermined scanning period is 1/N of the sending period; characterized in comprising: acquiring, by the touch control device, at least one frame of scanned data which is the invalid signal from the N frames of scanned data; using, by the touch control device, a value of a data frame of the at least one frame of scanned data which is the invalid signal as a strength of an LCD interference signal, wherein the data frame has a minimum signal strength; and reducing, by the touch control device, noise for the N frames of scanned data according to the strength of the LCD interference signal comprising: subtracting, by the touch control device, the strength of the LCD interference signal from the signal strengths of the remaining frames, i.e. of the N frames of scanned data respectively except for the data frame corresponding to the invalid signal. when the external device communicates with the touch control device, sending, by the external device, 1-bit data to the touch screen within each sending period, wherein the 1-bit data sent within each sending period is a combination of a valid signal and an invalid signal, or an invalid signal; scanning, by the touch control device, the 1-bit data based on a predetermined scanning period to obtain N frames of scanned data, wherein the predetermined scanning period is 1/N of the sending period; characterized in comprising: acquiring, by the touch control device, at least one frame of scanned data which is the invalid signal from the N frames of scanned data; using, by the touch control device, a value of a data frame of the at least one frame of scanned data which is the invalid signal as a strength of an LCD interference signal, wherein the data frame has a minimum signal strength; and reducing, by the touch control device, noise for the N frames of scanned data according to the strength of the LCD interference signal comprising: subtracting, by the touch control device, the strength of the LCD interference signal from the signal strengths of the remaining frames, i.e. of the N frames of scanned data respectively except for the data frame corresponding to the invalid signal. acquiring, by the touch control device, at least one frame of scanned data which is the invalid signal from the N frames of scanned data; using, by the touch control device, a value of a data frame of the at least one frame of scanned data which is the invalid signal as a strength of an LCD interference signal, wherein the data frame has a minimum signal strength; and reducing, by the touch control device, noise for the N frames of scanned data according to the strength of the LCD interference signal comprising: subtracting, by the touch control device, the strength of the LCD interference signal from the signal strengths of the remaining frames, i.e. of the N frames of scanned data respectively except for the data frame corresponding to the invalid signal.