The invention is an infusion alarm system centered on liquid level detection and a single-chip microcomputer, including a power supply module, a photoelectric sensor, a comparator, a single-chip microcomputer, an LED lamp, a sound alarm device and an executive mechanism. Among them, the liquid in the infusion tube is detected by a photoelectric sensor (photoelectric interrupter), and the infusion alarm system is controlled by a single-chip microcomputer. The device uses a photoelectric sensor to detect whether there is liquid in the infusion tube sensitively, quickly and accurately, and reduces the workload of escorts during infusion. Combined with the multi-task processing capability of the single-chip microcomputer, it can complete sound and light alarm, position display, address transmission and automatic clamping Infusion tube and other functions. The entire control system not only has low cost, less external interference, and sensitive liquid level detection, but also has the advantages of small size, easy installation and operation, and no need to remove drugs. It can be used in small-scale decentralized or large-scale centralized use in hospitals and other places where intravenous infusion is common.