The present invention discloses an asymmetric field ion mobility spectrometer. It comprises an ionization source, for generating ions; an electrode plate; a plurality of electrode filaments, arranged in opposite to and spaced apart from the electrode plate by an analysis gap, wherein a high voltage of electrical field is applied between the electrode plate and the electrode filaments to form an ion migration area, the electrode filaments used to collect the ions that do not pass through the ion migration area; and a collection electrode, disposed at a rear end of the ion migration area, and collecting the ions that have passed through the ion migration area. The present asymmetric field ion mobility spectrometer is capable of improving accuracy of identifying peak positions of the ions, reducing scanning time of DC voltage and types of compensation voltage, thereby increasing ion detection efficiency.