Maize is a globally important crop. Roots are the main part of maize and are mainly used for soil improvement and for maintaining crop growth as agricultural waste. Their application scope is relatively small. It is very important to analyze the components in maize roots in order to increase their resource utilization and reduce the burden of waste disposal. Metabolomics shows that maize roots contain various bioactive components, such as alkaloids, phenolic acids, flavonoids, etc. Therefore, this study explores the potential pharmacological effects of maize root metabolites under drought stress from the perspective of metabolomics combined with network pharmacology. The crude extraction of betaine, a metabolite in maize roots under drought stress, was conducted, and the anti-inflammatory and antioxidant effects of the crude extract were evaluated. The experimental results of DPPH, Fenton, etc. indicate that the crude extract of betaine from maize roots has certain anti-inflammatory and antioxidant effects, which provides a basis for its potential applications in the fields of medicine and food. The research on extracting medicinal active substances such as betaine from maize roots as agricultural waste not only has economic and environmental advantages but also has important significance in promoting technological progress and public health.