Flexible luminescent crystals have attracted increasing attention on account of the potential application value in optical material fields. How to design crystals with high elasticity and bright luminescence is an urgent duty that material researchers want to effectuate. Crystal engineering could achieve different crystal materials with various functions based on one molecular structure. Therefore, crystal engineering provides a potential strategy to improve the properties of flexible crystals. In this paper, we gave a pioneer work to improve the properties of flexible luminescent crystals by designing on crystal structure. By disclosing the relationship of structure-property, our work extracted the advantages (elasticity or bright emission) of two inferior crystals and obtained three elastic bending crystals with outstanding emission behaviors. Notably, our work not only achieves the fabrication of flexible crystals based on crystal engineering aspect but also provides good candidates for flexible optical waveguiding materials.