In today's information age, the amount of data as an important information carrier is growing at an explosive rate. The importance of its transmission rate, stability, accuracy and other properties is gradually becoming more and more important. UART as a communication protocol is widely used in embedded and IoT systems. It is simpler and more direct than SP2 and I2C, which can greatly simplify the complexity of digital circuits and become one of the key directions to improve the performance of data transmission. In this paper, a digital circuit based on the transmitter and receiver side of the UART protocol has been constructed using the hardware description language of Verilog HDL to implement the function of receiving and transmitting data based on a clock signal of 50 MHz and a baud rate of 115200 bps as well as the use of an RS232 asynchronous serial interface. The simulation was carried out using Quartus II.