The invention discloses a nanofluidic channel liquid chromatogram/mass spectrum method of soybean flavonoid metabolic profiling analysis. By the adoption of a simple sample pretreatment method, under the conditions of high enrichment capacity of channels and optimized segregation analysis, profiling analysis of 73 flavonoids can be realized by minimal sample size. The analysis method provided by the invention is simple and rapid, has advantages of small sample amount and good repeatability, and is suitable for batch analysis of real samples.