A quadrupole mass analyzer according to the present invention optimizes a stability band formation mode of a quadrupole system, so as to facilitate passing of ions and blocking of excessive ions, thereby improving the mass resolution without reducing the ion transmission efficiency. The solution of the present invention avoids the superimposition of high-frequency AC signals needed in the ion two-direction resonance frequency control in the prior art, and can effectively reduce the risk of quadrupole working performance reduction caused by the non-linear distortion of an RF voltage caused by bandwidth limitation in a fast RF circuit. In addition, a scanning speed of an ion-controlled electric field required by the quadrupole mass spectrometry can also be controlled faster because of reduction of limit bandwidth of various needed AC excitation signals. It is advantageous to obtain high-speed quadrupole scanning mass spectrometry performance.