A noise detection method including the following steps is provided. During different time periods, plural sets of driving signals are respectively transmitted to driving lines of the touch panel to drive sensing lines of the touch panel to generate plural sets of sensing signals. The plural sets of sensing signals are respectively received and calculated to obtain plural sets of summation signals. One set of summation signals includes first summation signals, and another set of summation signals includes second summation signals. A part or all of the first summation signals is replaced by the second summation signals. A signal value of a combination of the first and the second summation signals is calculated to obtain a summation thereof. The summation of the signal value of the combination is smaller than a summation of a signal values of the first summation signals before recombination.