The flow measurement of the natural gas directly influences the economic benefit, which includes development, operation, allotment and the utilization in the industry of the natural gas. Moreover the structure of the pipeline is the main factor for the accuracy of the flow metering. In this paper, the research on the internal flow field of various kinds of pipe structure with the remit pipe, which are the different inflows and whether equipped with the panel rectifier separately, is done with the method of the numerical simulation and the experiment. The conclusion shows that the desire length to recover the full development turbulence section in the downstream of the remit pipe is most in the pipe structure with the stagger inlet-outlet and no rectifier. While that in the pipe structure with the opposite inlet-outlet and with a rectifier reaches the least. It can be got that the most appropriate installation site of the flow meter and the design of the pipe structure of the natural gas from the research on the influence pattern of the gas flow field.