With the improvement of people's living standards, people's pursuit of quality of life is also increasing, enthusiast groups are growing, the demand for environmental control of the fish tank is increasingly refined and intelligent, and the ornamental fish industry has come into being. In this paper, we study a system based on STM32 microcontroller for detecting and controlling parameters such as temperature, light, PH, and water depth of the fish tank, and real-time displaying and controlling using the 2.8-inch LCD screen. In addition, the system supports remote control through the cell phone APP, and users can set up timed tasks or perform real-time operations as needed. Eventually, this project has researched and designed a smart fish tank system that can be remotely controlled, integrated with various functions and operated conveniently.