The optical scanner is one of the most important components in free-space optical communications, airborne and space-based lidars, adaptive optics, and so on. The performance of an optical scanner is frequently limited by the presence of mechanical resonances. This paper presents an analog notch filter with adjustable function to reject the mechanical resonances of the optical scanner. First of all, the structure and work principle of the piezoelectric optical scanner are introduced. Furthermore, the frequency sweep method based on virtual instruments is used to gain the natural frequency of the piezoelectric optical scanner. Then, the notch filters in series are used to reduce the oscillation of the scanner at the resonance frequencies. A variety of scanning experiments were carried out. After the introduction of the notch filter, the non-linearity was reduced to ±1.1% from ±2.1%. The linearity performance was greatly improved.