Abstract: The match relationship among technological conditions of Cu-Cr alloy, during continuous unidirectional solidification has been studied. Microstructure of Cu-Cr alloy and the reason for formation of surface defect in Cu-Cr alloy have been analyzed. The best technological conditions are:height of mold is 10-25 mm, cooling distance is 25 mm, melting temperature of Cu-Cr alloy is 1 280℃, Withdrawal speed is 0.24-1.00 mm/s, amount of cooling water is 720 L/h.