Abstract In this work, we study the development, evolution and migration of turbulent coherent structures in the turbulent boundary layer at using time-resolved particle image velocimetry (TR-PIV). Multiple techniques, including multi-scale analysis, conditional averaging, cross-correlation and spatial-temporal topological analysis are applied to extract the evolution principle, migration trajectory and convection velocity vector of the targeted coherent structures from a Lagrangian perspective. The spanwise vortex structures with larger scale and intensity at a certain wall-normal height were the main focus of the present study. In the statistical sense, spanwise vortex structures move away from the wall with the shape changes from a bulge to an ellipse, and finally to a circle. Two straight lines emerge from the mean transfer trajectory curve of spanwise vortex, in which the horizontal one is located at the viscous sublayer ( ), the other is a logarithmic straight line existing in the range of and the inclination angle of the tangential migration path is fixed at around . The streamwise convection velocity of scaled spanwise vortex structures satisfies below (i.e. under ). In particular, in the region of , the velocity growth curves of and wall-normal convection velocity follow the log-law distribution very well, and the slopes are consistent with that of log-law region of turbulent boundary layer. Our observations provide microscopic evidences to the logarithmic-linear distribution of the migration trajectory of spanwise vortex structures.