The invention relates to a peak voltage-variable trapezoidal pulse generation circuit and belongs to the electronic circuit technical field. According to the peak voltage-variable trapezoidal pulse generation circuit provided by the invention, a capacitor is charged slowly through a MOS tube when an external clock signal is at a low electric level; when the low electric level of the external clock signal is turned over and is converted into a high electric level, the voltage of the capacitor achieves the peak voltage of a trapezoidal pulse, and at this moment, the holding time of the peak voltage begins; the external clock signal can be converted into a high-electric level spike pulse with a very small duty ratio through a clock conversion circuit; and the high-electric level signal of the spike pulse starts an NMOS tube, so that fast discharging can be performed on the capacitor, and the voltage on the capacitor drops to zero. The circuit of the invention can generate the trapezoidal pulse, and the peak voltage, the duty ratio, the rising time and drop time of the trapezoidal pulse can be changed according to application demands. The peak voltage-variable trapezoidal pulse generation circuit of the invention is particularly applicable to the electronic circuit field which has relatively flexible and variable requirements for pulses.