Abstract: Direct mass spectrometry, a cutting-edge analytical technique developed in recent decades, has fundamentally transformed conventional sample analysis paradigms. It allows for the direct interrogation of samples under ambient, open-air conditions without the need for laborious and time-consuming sample pretreatment or preparation. This innovative methodology combines a unique set of advantageous features. Notably, it facilitates real-time, in situ analysis, offering remarkable operational simplicity, rapid turnaround, and high-throughput capability, all while being more environmentally benign by minimizing solvent use and waste generation. Concurrently, it inherits and upholds the quintessential strengths of traditional mass spectrometry, namely exceptional analytical speed, high sensitivity, and excellent specificity. This group of techniques encompasses several prominent methods, including but not limited to desorption electrospray ionization (DESI), direct analysis in real time (DART), and paper spray ionization. Each technique operates via unique mechanisms for desorbing and ionizing analytes directly from solid, liquid, or gaseous samples. Owing to this powerful combination of attributes, direct mass spectrometry analysis has found extensive and promising applications across a diverse spectrum of scientific and industrial domains. Its utility is increasingly recognized in medical diagnostics and biomarker discovery, pharmaceutical research and quality control, the monitoring of food contaminants for safety assurance, the analysis of environmental pollutants, and the authentication and quality assessment of traditional herbal medicines, including Chinese medicinal materials. Given this broad impact, the technique has garnered considerable and sustained attention from the mass spectrometry community. Research efforts are intensely focused on two primary fronts: the continuous innovation and refinement of novel ambient ionization sources that are the core of this technology, and the development of robust methodologies for the reliable qualitative identification and accurate quantitative determination of target analytes in complex, real-world sample matrices. The present work aims to provide a comprehensive overview of this dynamic field. It starts by elucidating the fundamental operational principles and distinctive characteristics of several mainstream direct mass spectrometry analysis techniques. Furthermore, it provides a comprehensive review of their application advancements over the past decade in a specific, high-value domain: the analysis of pharmacologically active constituents (e.g., ginsenosides, polysaccharides) in plants of the medicinally vital Panax genus (e.g., ginseng, notoginseng). Finally, the article ends with a forward-looking perspective, examining future trends and potential breakthroughs. It is posited that direct MS analysis is poised to play a pivotal role in advancing research on “Daodi”, or genuine regional medicinal materials, offering powerful tools for origin traceability, quality grading, and the study of genotype-environment-phenotype interactions, thereby bridging traditional knowledge with modern analytical science.