The Xiaobeiganliu reach of the middle Yellow River is a braided reach, and the main-channel of this reach often migrates, so investigating the characteristics of main-channel migration is crucial to understand the river regime adjustments and fluvial processes of the Xiaobeiganliu reach. In this study, main-channel migration widths and intensities at section- and reach-scales were calculated based on post-flood remote sensing images and 29 observed cross-sectional profiles in the Xiaobeiganliu reach during the period from 1986 to 2001, in order to investigate the characteristics of main-channel migration and to analyze the influencing factors of main-channel migration intensities quantitatively. Calculated results indicate that: (ⅰ) the main-channel migration processes were reciprocating, and section-scale main-channel migration widths in the upper reach were larger than those in the middle and lower reaches; (ⅱ) the width and intensity of main-channel migration of the Yumenkou-Miaoqian reach were 1151 m/a and 0.70, respectively, and it was the most dramatic reach in terms of the main-channel migration in the Xiaobeiganliu reach; (ⅲ) the main-channel migration intensity can be represented by empirical functions of two key hydrodynamic parameters, covering the upstream boundary condition(the previous three-year average incoming sediment coefficient), and the downstream boundary condition (the variation in Tongguan elevation); (ⅳ) higher values of incoming sediment coefficient and Tongguan elevation caused a larger main-channel migration intensity, which contribute about 89.3% and 10.7%, respectively, and it indicates that the incoming flow and sediment regime is the dominant factor affecting the main-channel migration in the Xiaobeiganliu reach, and the Tongguan elevation is the secondary factor; and (v) it is verified that the calculated main-channel migration by using the empirical equation agreed well with the observed data, so the empirical equation can be used to calculate and predict the processes of the main-channel migration in the Xiaobeiganliu reach during the continuous siltation period.