Aimed at a decline in interference effect, a smart noise mathematical model is buit up based on sinusoidal modulation in accordance with convolution modulation in the time domain,and then a smart noise jamming is designed based on incomplete sinusoidal convolution modulation to realize interference with linear frequency modulation signal. The result of simulation shows that the interference signals can produce false targets group to cover the real echo signals of a certain distance unit, which can also be easily covered by the nonlinear superposition sidelobe.By so doing, the defect of convolution jamming signal being behind the real target echo is overcomed.