Abstract: The present invention provides a high throughput method for constructing and screening a compound library and a reaction device. Specifically, the method of the present invention comprises: (a) providing a reactor comprising n independent and addressable reaction chambers; (b) performing m independent synthesis reactions in said n reaction chambers, thereby constructing a compound library; and (c) performing activity tests in reaction chambers in which synthesis reactions are performed. In the present invention, the preparation and screening processes of a compound can be completed in the same reaction system. As the reactions of the present invention almost quantitatively generate products, the products can be directly used in enzymatic or even cytological activity test experiments without separation.