The present application provides a gas alarm replacement warning method and device, and an electronic apparatus including the device. The method is applied to a gas alarm including a gas-sensitive element. The method includes: collecting signal data of the gas alarm; analyzing the current use state of the gas alarm based on the signal data; determining a dynamic model of the expected service life of the gas alarm according to the current use state, and calculating the expected use duration of the gas alarm; determining whether the actual use duration of the gas alarm is greater than the expected use duration; and if so, outputting a replacement prompt signal. Therefore, based on the expected service life of the gas alarm, when the use duration of the gas alarm approaches the expected service life, a replacement prompt signal is issued to solve the problem of untimely replacement of the gas alarm and ensure the safety of indoor gas use.