Provided is a spatial focusing ion mobility tube, including an ionzation source, an ion gate, a grid mesh and a faraday disc. A focusing grid mesh parallel to the ion gate is provided at one side of the ion gate away from the ionization source, and the ion gate and the focusing grid mesh combine into a spatial focusing ion gate assembly which controls the flight of the ions. The mobility tube employs a traditional design and changes the ion gate portion to one or more spatial focusing ion gate assemblies. The spatial focusing assembly can realize the injection function of the ion gate and produce the spatial compression focusing of ions.