Benefiting from the easily adjustable optical properties of perovskite, CsPbBr3 nanocrystals (NCs) are considered to show their advantages in the field of display. Here, we report that a selective laser irradiation is used to induce CsPbBr3 nanostructural reshaping and then yielding a morphological change. Under 360 or 405 nm laser irradiation, a hierarchical crystal growth process occurs for the fabricated CsPbBr3 nanoplatelets (NPLs), which are first arranged in a side-by-side manner and reshaped into nanorods (NRs), and then NRs are arranged in the face-to-face manner to reshape into NCs. The entire process is monitored optically and microscopically, which showed that crystal growth relies on seeking a dynamic balance between heat dissipation and accumulation under laser irradiation. The heat on NPLs generated by laser irradiation dissipated with a low dissipation rate and thus led to temperature rising and lattice breaking, which turned out to be the driving force for the crystal growth in CsPbBr3 NPLs. This feasible laser irradiation-assisted method provides for crystal growth a reliable and scalable route toward the preparation of perovskite functional materials.