As a new type of porous crystalline material, covalent organic frameworks (COFs) have shown great potential in many application fields. Postsynthetic modification (PSM) is a prevalent and useful strategy for producing new COFs with desired functionalities. Herein, we report a general method for COF post-functionalization that involves the introduction of amino functional groups (–NH₂) into the framework as anchoring sites. By this strategy, a variety of COFs with desired functionalities were prepared under ambient conditions by transforming –NH₂ into imine, thiourea, amide and azo-based functional groups. We believe this work will provide an opportunity to create porous materials with augmented properties and performances and expand their practical application.