The surface roughness measurement is experimentally researched by using angular-speckle correlation method on blasted sand surface. Through the data processing and analysis of laser speckle patterns, moving correlation algorithm was presented to get the maximal angular-speckle correlation coefficients. This method can avoid the negative effects of surface flatness and waviness effectively. Under the prime measurement condition, the optimal incident angle increment of laser beam was given, and a method of surface roughness measurement including speckle pattern acquisition and processing was developed. The key of this method is that far-field speckle patterns in different incident angles and illumination areas of rough surface are detected and processed. The experimental results indicate that prime root-mean-square (RMS) deviation measured by this method is almost linear with the arithmetical mean deviation of the surface-samples.