In response to the problems of low measurement accuracy, non-intuitive display, and lack of cumulative measurement function in traditional float flowmeters used in medical oxygen generators, an intelligent oxygen flow monitoring system based on a strain gauge sensor was designed. The system adopts a single-ended fixed cantilever-beam strain gauge structure, combined with an improved Wheatstone bridge and a high-precision instrumentation amplifier, to achieve sensitive capture and efficient conversion of weak strain signals caused by gas flow. A voltage-flow rate polynomial equation was fitted using MATLAB, and Kalman filtering with a self-correction algorithm was introduced to effectively suppress temperature drift and noise interference, thereby enhancing the measurement stability and reliability of the system in complex environments. The experimental results are as follows: within the measurement range of 0.5~5 L/min, the maximum absolute error of the sensor is less than 0.2 L/min under ambient temperatures ranging from -10 ℃ to 40 ℃, with a response time of less than 2 s; the output remains stable during 168 h of continuous operation, with no significant drift or failure observed; and the measurement stability is well maintained under pressure variations from 86 to 106 kPa. The results indicate that the system is capable of real-time display of instantaneous flow rate and cumulative oxygen consumption, featuring a simple structure, low cost, high accuracy, and strong environmental adaptability. It provides a reliable solution for the intelligent upgrading of medical oxygen generators.