A method of optimizing a signal-to-noise ratio SNR parameter, comprising steps of: obtaining a capacitance signal of a touch screen without being touched and a capacitance signal of the touch screen being touched, respectively; filtering the capacitance signal of the touch screen without being touched to obtain a first filtered capacitance signal; filtering the capacitance signal of the touch screen being touched to obtain a second filtered capacitance signal; calculating an average value of the first filtered capacitance signal in a single period and an average value of the second filtered capacitance signal in the single period; compensating the average value of the first filtered capacitance signal or the average value of the second filtered capacitance signal; and determining the SNR parameter, according to a first ratio of the compensated average value of the second filtered capacitance signal to the average value of the first filtered capacitance signal and a correspondence between the first ratio and the SNR parameter, or according to a second ratio of the average value of the second filtered capacitance signal to the compensated average value of the first filtered capacitance signal and a correspondence between the second ratio and the SNR parameter, wherein the step of compensating the average value of the second filtered capacitance signal comprises: obtaining a preset first compensation parameter, the first compensation parameter being not less than 1; and taking a product of the first compensation parameter and the average value of the second filtered capacitance signal as the compensated average value of the second filtered capacitance signal, and wherein the step of compensating the average value of the first filtered capacitance signal comprises: obtaining a preset second compensation parameter, the second compensation parameter being not larger than 1; and multiplying the second compensation parameter with the average value of the first filtered capacitance signal to obtain a second product as the compensated average value of the first filtered capacitance signal. obtaining a capacitance signal of a touch screen without being touched and a capacitance signal of the touch screen being touched, respectively; filtering the capacitance signal of the touch screen without being touched to obtain a first filtered capacitance signal; filtering the capacitance signal of the touch screen being touched to obtain a second filtered capacitance signal; calculating an average value of the first filtered capacitance signal in a single period and an average value of the second filtered capacitance signal in the single period; compensating the average value of the first filtered capacitance signal or the average value of the second filtered capacitance signal; and determining the SNR parameter, according to a first ratio of the compensated average value of the second filtered capacitance signal to the average value of the first filtered capacitance signal and a correspondence between the first ratio and the SNR parameter, or according to a second ratio of the average value of the second filtered capacitance signal to the compensated average value of the first filtered capacitance signal and a correspondence between the second ratio and the SNR parameter, wherein the step of compensating the average value of the second filtered capacitance signal comprises: obtaining a preset first compensation parameter, the first compensation parameter being not less than 1; and taking a product of the first compensation parameter and the average value of the second filtered capacitance signal as the compensated average value of the second filtered capacitance signal, and obtaining a preset first compensation parameter, the first compensation parameter being not less than 1; and taking a product of the first compensation parameter and the average value of the second filtered capacitance signal as the compensated average value of the second filtered capacitance signal, and wherein the step of compensating the average value of the first filtered capacitance signal comprises: obtaining a preset second compensation parameter, the second compensation parameter being not larger than 1; and multiplying the second compensation parameter with the average value of the first filtered capacitance signal to obtain a second product as the compensated average value of the first filtered capacitance signal. obtaining a preset second compensation parameter, the second compensation parameter being not larger than 1; and multiplying the second compensation parameter with the average value of the first filtered capacitance signal to obtain a second product as the compensated average value of the first filtered capacitance signal.