This study aims to apply CsPbBr₃ perovskite quantum dots, known for their excellent luminescent properties, to fiber-based quantum cryptography. To achieve this, quantum dot samples were fabricated by spin-coating perovskite colloidal solutions onto Si substrates under varying process conditions. The photoluminescence (PL) characteristics of the ensemble quantum dots (ensemble QD) were analyzed at both room temperature and low temperature (~4 K) using micro-PL measurements. Additionally, quantum dot-fiber coupling was attempted using polydimethylsiloxane (PDMS) and an optical microscope. Furthermore, finite-difference time-domain (FDTD) simulations were employed to design a free-form intermediate structure to enhance quantum dot-fiber coupling efficiency. The results suggest that perovskite quantum dots can be integrated into fiber-based quantum communication. In the future, securing single quantum dots (single QD) and incorporating them into the designed structure could enable high-efficiency quantum dot-fiber coupling for quantum cryptographic communication.