The important non-protein amino acid β-N-oxalyl-L-α, β-diaminopropionic acid (β-ODAP) in Lathyrus sativus and dencichine in Panax notoginseng are the same secondary metabolite. It has various biological activities, such as hemostasis, nerve stimulation, antibacterial, etc.. Since it was discovered in L. sativus and other legumes in the 1960s, and in P. notoginseng and other plants in the 1980s, many detection methods for β-ODAP have been developed. In this review, the basic principles and applications of these methods, including traditional analysis, high performance liquid chromatography (HPLC), chromatography-mass spectrometry (GC/LC-MS), capillary electrophoresis and enzymatic analysis, were assessed and compared. Generally, these methods have their own strengths, and the specific choice depends on the experimental conditions and experimental purposes. Among them, HPLC with pre-column derivatization is currently the most widely used method, while high-cost LC-MS with isotope internal standard is known as the “gold standard”. However, it is the pursuit of goals that the specific, rapid and low-cost strategy for β-ODAP determination to be developed. The improvement of enzyme sensor technology is therefore the main research direction for β-ODAP detection in the future.