The effect of laser repairing process of single-crystal superalloy on the dendrites growth, and the effect of bottom angle of V-groove on the dendrites growth are analyzed. The proper process is determined through laser cladding on the DD5 sample, and it is revealed that the decrease of heat input is beneficial to broaden the zone of directional dendrites. By overlapping experiment on the DD5 sample, it is found that the overlapping rate of 30% benefits the consistency of the dendrites growth in cladding region. With appropriate process parameters, V-grooves of different bottom angles in the DD6 sample are repaired. The results show that changes in the bottom angle of the V-groove from 60° to 120° have little effect on the dendrites growth direction at the bottom. The number of stray grains near the side wall decreases as the angle between the direction of molten pool temperature gradient and the optimal growth direction increases. The stray grains are eliminated in the region of side wall when the bottom angle is 120°.