The parallel orifice plate is usually used to measure natural gas transported by pipeline. However, when the orifice plate is raised to the upper chamber during periodic cleaning, it will inevitably lead to flow dynamic redistribution in the pipeline, resulting in measurement errors that directly affect the profit of the enterprises. At present, there is no qualitative and quantitative analysis and research on the influencing factors and compensation methods of measurement error caused by flow dynamic redistribution. Therefore, based on the basic principle of computational fluid dynamics, Fluent software was used to build a threedimensional flow field model in the parallel orifice metering device, and analyze the flow dynamic redistribution pattern during the periodic cleaning of the orifice plate. The research results indicate the following. First, the flow compensation coefficient is independent of pressure and temperature. Second, in the parallel metering device with the same aperture, the compensation coefficient increases with the increase of total gas volume, pipe diameter, relative density, and the number of parallel pipes, and decreases with the increase of pipe diameter ratio, of which the pipe diameter ratio is the main controlling factor. Third, in the parallel metering device with different apertures, the compensation coefficient increases with the increase of total gas volume, pipe diameter and relative density, and decreases significantly with the increase of parallel aperture diameter ratio, of which the parallel aperture diameter ratio is the main controlling factor. Furthermore, based on the research results, the flow compensation coefficient correction equation was developed, and the measurement deviation is significantly reduced by field test, which greatly reduces the potential profit loss caused by inaccurate measurement.