Abstract: With the rapid popularization of Internet of Things and embedded technology, traditional vending machines are upgrading towards intelligence, networking and unmanned operation. This paper designs an IoT-based vending machine system with STM32F103C8T6 microcontroller as the core controller, integrating TFT color screen display, stepper motor drive, WiFi wireless communication, independent key input and buzzer alarm modules. The system supports both on-site payment and QR code payment, and uses WiFi module to realize data exchange between the device and mobile APP. After hardware construction, software programming, Proteus simulation and full-process testing, the system can stably realize core functions such as product selection, payment, dispensing and inventory management.