The ward call system based on the 51 microcontroller is designed to improve communication between medical staff and patients, enhance the quality of hospital services. The system is composed of a buzzer, digital tube, indicator light, buttons, and microcontroller. When a patient in the ward needs help, they can press the call button, and the on-duty personnel in the duty room can see the corresponding room number and bed number on the display, and then arrange and implement the patient's needs. If multiple people press the button at the same time, they can be arranged according to the actual situation, prioritizing the needs of the seriously ill patients. In addition, the system uses wired communication, which is safe and reliable and does not interfere with the normal operation of other medical electronic devices. However, installation is cumbersome, maintenance is inconvenient, and timeliness is relatively low. Keywords: ward call; microcontroller; serial port display documentation for reference only.