The fiber laser spot welding process is studied with the high-frequency laser focus rotation method and compared with the traditional laser spot welding processes. The results show that, under the thermal conduction welding mode, the spot weld morphology can be effectively controlled by using the heat accumulation effect from the laser focus high-frequency repetitive scanning and the adjustment of the laser rotation process parameters. With the further heat accumulation, the spot weld morphology changes from the double “V” shape to the “W” shape and until to the “U” shape. Compared with those for the traditional laser spot welding process, the width-depth ratio of the spot welds is relatively larger for the high-frequency focus rotation spot welding process and substantially free of porosity defects. Simultaneously, the microstructure and microhardness of spot welds can be effectively regulated by the proposed method.