Quantum key distribution (QKD) technology exhibits significant application demand in data security-sensitive fields such as military, government, finance, and healthcare. However, the deployment of conventional QKD systems typically requires large-scale specialized equipment and dedicated fiber connections, which substantially limits the flexibility of application scenarios and deployment efficiency. Although existing research has explored the potential of QKD in Internet of Things (IoT) environments, the specific challenges imposed by current hardware conditions and device limitations have not been thoroughly investigated. This study proposes a QKD framework that further decouples the receiver as a dedicated interface device and a mobile terminal (e.g., smartphones) for key distribution. Specifically, in continuous-variable quantum key distribution (CV-QKD) scenarios, mobile terminals can connect with QKD devices through dedicated interface devices to accomplish initial key distribution, while subsequent key negotiation is conducted through wireless communication. This architecture enables the execution of final post-processing operations by specialized devices even under physically disconnected conditions. The proposed solution effectively addresses the technical challenges of deploying QKD on computationally constrained terminal devices (e.g., IoT devices), thereby significantly expanding the application scope and practical feasibility of QKD technology.