An inert gas nucleus channel device comprising a magnetic resonance control system, a radio frequency generator, an RF amplifier and AD converter, a frequency synthesizer, a first mixer, a second power amplifier, a second T/R switch, an inert gas nucleus coil, a second pre-amplifier and a second mixer. A magnetic resonance imaging method is also disclosed. The method controls an increase or decrease in a frequency of a pulse or echo signal excited by a radio-frequency signal, implementing magnetic resonance imaging using hyperpolarized inert gases (such as xenon, helium, and krypton), making it possible to apply MRI to lungs and brains using the hyperpolarized inert gases, and expanding the probing range of MRI. The inert gas nucleus channel device is simple in structure and easy to operate and upgrades a hydrogen nucleus magnetic resonance imaging instrument to become a multi-nuclei MRI system using the hyperpolarized inert gases.