The migration of plasticizers in soft polyvinyl chloride (PVC) products, which brings the deterioration of material properties and environmental pollution, has attracted much attention. Poly(ε-caprolactone) (PCL) can serve as macromolecular plasticizer to solve the problem of plasticizer migration due to its excellent compatibility with PVC. However, PCL is prone to crystallization in PVC/PCL blends, which affects the plasticizing effect during long-term use. In this work, the effects of plasticizers with different structures on the crystallization behavior of PCL in the PVC/PCL/plasticizer blends were investigated. The polarized optical microscopy (POM) and differential scanning calorimeter (DSC) results show that the structures (such as benzene rings, short-chain alkyl groups, hydroxyl groups) of the plasticizer affect the crystallization behavior of PCL in the blends by changing their interaction intensity with PCL. Meanwhile, the compatibility of plasticizers with PVC has an indirect regulatory effect on the crystallization of PCL. This study provides a theoretical basis for the synergistic inhibition of plasticizer migration through the combination of PCL and small-molecule plasticizers.