In order to explore the effect of different guide strip lengths on the annular gap flow field and transport speed of pipe vehicle, the transport speed and annular gap flow field of pipe vehicle with guide strip lengths of 0, 35, 75, 112.5, and 150 mm were studied through model tests. The results show that the movement speed of pipe vehicle and the annular gap flow velocity are changed by adding guide strip, and the two have a negative correlation. With the increase of the length of guide strip, the speed of pipe vehicle increases gradually, while the flow velocity of annular gap decreases. When the length of guide strip is 150 mm, the speed of pipe vehicle reaches the maximum. The distribution trends of axial and radial flow velocity in annular gap are approximately the same under different guide strip lengths,that is, the direction along the pipe vehicle wall to the pipe wall shows a trend of increasing first and then decreasing, but the positions of the maximum values of axial and radial velocity are different. The circumferential flow velocity in annular gap gradually decreases along the pipe vehicle wall to the pipe wall. The research further enriches the gap flow theory and provides a certain theoretical basis for the selection of guide strip and the optimization design of pipe vehicle.