As an efficient method to accelerate the process of drug discovery, fragment screening has been widely recognized in academic and commercial fields. The FBDD method usually first determines the affinity of a water-soluble small molecule compound (relative molecular mass<300, ie, a fragment molecule). Although the binding force is weak (usually a few hundred micromolar or millimolar level), the combination is mostly driven by a hydrazine factor such as a hydrogen bond or a salt bond, so that the atomic utilization ratio of the compound is high and the number of redundant atoms is small. Structural biology (X-ray diffraction or 2D-NMR) is used to show the spatial orientation and binding characteristics of the fragment in the target protein. Under the guidance of the microstructure, the binding strength is increased by the growth or linkage of the fragments, and the lead compound molecules with high activity and high quality are obtained.