Based on the shortcomings of traditional trash cans and existing smart trash cans, this paper designs a smart trash can system and performs 3D modeling of the smart trash can. The system integrates voice recognition technology, infrared sensor technology, ultrasonic sensor technology, and solar charging technology. The system adopts a double-box design, with ESP32-WROOM as the controller, and uses an offline voice recognition module to control the opening of the trash can lid. The lid of the trash can is closed by an infrared sensor, and the ultrasonic sensor determines the overflow state by detecting the height of the garbage. The lithium battery is charged by a solar panel and a solar charging module. After testing, the voice recognition success rate of the smart trash can system is as high as 96%, which is very suitable for use in libraries, offices, and home living places. The implementation of the smart trash can system provides users with a high-experience, high-automation, and high-reliability solution. In the future, remote monitoring and data collection can be achieved through the Internet of Things technology.