Step-shaped spur dike is widely used in channel regulation. As one of the important coherent structures of turbulence，the spatial correlation structure of velocity fluctuations can effectively reflect the flow field characteristics around step-shaped spur dike area. Based on PIV test data of turbulent flow of step-shaped spur dike area in open channel，the distribution characteristics of spatial auto-correlation and cross-correlation structure of velocity fluctuations in step-shaped spur dike area are analyzed，and the variation of two-point spatial correlation structures of velocity uctuations along streamwise，wall-normal and spanwise are studied. The results show that the auto-correlation of the streamwise velocity fluctuations Cuu and the auto-correlation of the wall-normal velocity fluctuations Cvv are both positive. The value of the autocorrelation coefficient is in the interval of 0.3 to 0.9，the distribution range decreases with the increase of water depth，and increases with the increase of the distance from the step-shaped spur dike. The cloud map of the cross-correlation coefficient of streamwise and wall-normal velocity fluctuations Cuv and the cross-correlation coefficient of wall-normal and streamwise velocity fluctuations Cvu in the near dike area has a basically symmetrical positive and negative partition phenomenon within the length of the first-level spur dike downstream of the spur dike. The distribution range of contour lines with strong correlation in the cloud map of Cuv and Cvu near the first step-shaped spur dike is larger in the area near the dike and smaller in the center of the flume. Near the center of the flume，the contour lines with the larger absolute value of the spatial cross-correlation coefficient of the velocity fluctuations are basically distributed above the secondary spur dike，Cuv is positive，Cvu is negative.