To solve the problem of the reduction in the position accuracy of the laser spot centroid caused by laser random speckle in the high-precision visual positioning measurement system， the speckle mechanism and suppression methods were studied. First， the causes of laser random speckle in the laser spot imaging process were analyzed， and the expression for the total wave disturbance at any point in space was derived. Then， a model for the relationships among the light absorption， roughness of the imaging medium， surface outgoing light signal-to-noise ratio， and random speckle intensity was established. It is concluded that increasing the roughness and light absorption of the imaging medium can increase the signal-to-noise ratio of the outgoing light and thus reduce the random speckle intensity. Finally， comparison experiments were performed to obtain the trend chart of the stability of the spot centroid position with changes in the physical characteristics of the imaging medium， and the results validated the relationship model. The experimental results indicate that when the laser power is 50 mW， the imaging medium had strong light absorption， and the imaging target surface had moderate roughness and thickness， the stability of laser spot centroid extraction is within 0.04 pixels. Laser speckle is suppressed， the stability of imaging spot coordinate extraction is improved， and the accuracy of spot centroid positioning is increased.