Mass spectrum ion source apparatus in low-vacuum condition

The invention belongs to the technical field of mass spectrum analysis test, and specifically relates to a mass spectrum ion source apparatus in a low-vacuum condition. The apparatus comprises a vacuum system, and an ion source, a sample platform, an ion transport system, an ion quality analyzer and an ion detector arranged in the vacuum system; the vacuum system can realize a multi-stage vacuum differential function; ions generated by the ion source hit against the surface of a to-be-tested sample, and the to-be-tested sample suffers from sputtering and desorption after collision of ions to generate gas phase sample ions, so as to realize an ionization process of the to-be-tested sample; the generated to-be-tested sample ions enter the ion quality analyzer through the ion transport system; and by virtue of adoption of the vacuum system, the ion generation efficiency can be improved, and loss in the ion transport process can be lowered, thereby improving ion transmission efficiency anddetection sensitivity of