The present invention provides a gas meter query method based on a compound Internet of Things (IoT) and an IoT system, and relates to the field of the IoT. The method includes: sending, by the first gas meter of a plurality of gas meters, when reading the data information corresponding to the second gas meter, the data information to the management platform via the sensor network platform; sending, by the management platform, the first control signal to the second gas meter via the sensor network platform, so that the second gas meter sends the first prompt information; sending the second prompt information to at least one of a plurality of service sub-platforms; and sending, by one of the service sub-platforms that receives the second prompt information, the second prompt information to the user sub-platform corresponding to the second gas meter.