A touch control detection system, a delta-sigma modulator and a modulating method thereof are provided. The delta-sigma modulator includes a quantizer and N integrating units. The quantizer generates a modulating result signal. The integrating units are coupled in series. Each of the integrating receives an input signal, and each of the integrating units receives a plurality of gain parameters, N is a positive integer. The quantizer quantizes a signal on an output end of the Nth stage integrating unit according to an error signal for generating the modulating result signal. A center frequency of a noise transfer function (NTF) of the delta-sigma modulator is adjusted according to the gain parameters, and the gain parameters are determined according to a frequency of the input signal.