Considering chiral covalent organic frameworks (COFs) featuring the intriguing properties of porous organic materials, chiral recognition, and separation, the design and synthesis of chiral COFs with high crystallinity has remained a daunting challenge. A brominated functionalized COF (COF-Br) with high crystallinity and stability was synthesized. Using the post-synthetic modification strategy of the Suzuki–Miyaura cross-coupling reaction, a chiral COF (COF-L-Phe) was successfully constructed by combining COF-Br and the chiral functional groups of 4-borono-L-phenylalanine. The chiral recognition ability of COF-L-Phe was verified using an experimental adsorption model. Furthermore, COF-L-Phe-modified capillary columns have been used for the separation of racemic phenylalanine using capillary electrochromatography. This work will provide guidance for constructing chiral COFs for chirality related applications.