Abstract: Traditional ion sources generally require complex sample pre-processing for the analytes, which is time-consuming and labor-intensive, and cannot meet the requirements of rapid on-site detection, this problem greatly restricts the scope of application of the mass spectrometer. Atmospheric pressure ion source is a new type of ionization technology which has emerged in the last ten years, and it is also one of the hotspots in the application of mass spectrometry technology in life sciences, environmental protection, medicine and health, food safety and other fields. With the wider application of mass spectrometry technology, direct and rapid analysis of the composition and content of complex system has become more and more important. Based on the developed miniaturized ion trap mass spectrometer and electric-filter paper spray ion source, this paper conducted in-depth experimental research on their analytical performance and application. With the aim of improving the signal intensity and detection sensitivity of the mass spectra, the aperture of the filter paper, the angle between the tip of the ion source and the horizontal plane, the distance between the ion source and the mass spectrometry injection capillary, and the material of the metal funnel were systematically optimized. The experimental results showed that when the filter paper with a pore size of 20-25 μm, the angle between the ion source tip and the horizontal plane is 15°-60°, and the distance between the ion source and the mass spectrometry injection capillary is 7.5 mm, the signal intensity is the highest, the used different metal materials have little effect on the signal intensity of the ion source. Under the optimized experimental conditions, standard samples of sucrose, kemptide, vitamin B₂, rocuronium, arginine and fentanyl were tested, which greatly expanded the application range of the ion source. Analysis and detection of ammonia plus Huangmin capsules could quickly obtain the molecular ion peak of paracetamol (m/z 152), and the malachite green (m/z 329) molecular ion peak could be quickly detected in the living fish. In summary, the electric-filter paper spray ion source can realize rapid real-time detection and analysis, and reduce the complicated pre-processing process of the analytes. Furthermore, it can improve the sample analysis speed, and expand the application field of ion trap mass spectrometry technology.