Gas flow measurement is widely used in respiratory monitoring, pipeline transport, and other fields. In this study, the thermal boundary layer parameters in the one-dimensional temperature distribution model of MEMS calorimetric sensors are carefully analyzed, and the corresponding empirical corrections are made. On the basis of the one-dimensional temperature distribution model, a new semicorrected theoretical model of the sensor voltage output with respect to the gas flow rate is proposed for MEMS calorimetric sensors with two pairs of upstream and downstream temperature measuring resistor chip structures. The theoretical model can be applied to different types of single-medium gases. Meanwhile, N2 and CO2 flow measurement experiments are implemented to compare with the theoretical model, which shows that the proposed theoretical model can accurately predict the flow of different gases, and the RMSE is 0. 15% for the CO2 measurement medium. In addition, combined with the theoretical analysis, a high-precision measurement model with a simple fitting form and a better applicability to deterministic gases is proposed, and the RMSE is 0. 05% for the CO2 measurement medium