The embodiments of the present disclosure provide a method and system for monitoring ultrasonic metering based on smart gas Internet of Things implemented based on a system for monitoring ultrasonic metering, the system includes a smart gas user platform, a smart gas service platform, a smart gas device management platform, a smart gas sensor network platform, and a smart gas object platform that are connected in sequence. The method includes: in response to a query instruction issued by the smart gas user platform, obtaining target monitoring data at a target time point, a first monitoring data sequence within a first preset time period, and a second preset time period within a second preset time period; judging whether the target monitoring data being interference data through an interference data determination model; and in response to the target monitoring data being the interference data, performing interference processing on the interference data.