Single-phase IoT smart electricity meter is an important carrier of the construction of "ubiquitous power Internet of things". As the most basic function of the electricity meter, the measurement accuracy consistency is particularly essential. This paper takes a mainstream single-phase IoT smart electricity meter as an example. Through the analysis of the design scheme, a simulation analysis model of measurement unit circuit is established based on Simscape. This paper proposes an evaluation method for the consistency of the measurement accuracy of the IoT smart electricity meter through the introduction of Monte Carlo method, and proposes a measurement accuracy consistency optimization idea considering the tolerance range of components. The results show that the consistency of the measurement accuracy of the single-phase IoT smart electricity meter can be improved by increasing the accuracy level of the key components.