In the process of soft-contact electromagnetic continuous casting of 7050 aluminum alloy, the forced flow of molten melt is produced by the intermediate magnetic field, which can improve the microstructure and eliminate hot cracks. On one hand, the electromagnetic filed can reduce the external factors for hot cracking through improving the casting condition to decrease the temperature gradient, to release the thermal stress and strain and to make alloying brittleness zone mainly in the state of being compressed. On the other hand, it also can decrease the hot cracking tendency of alloys by reducing the size of unfeeding zone and decreasing the quantities of eutectic compounds of low melting point. As a result of the two facts above, the cracking of electromagnetic continuous casting slab is eliminated