Abstract: Analyzed are the causes for the common quality problems as staying with the company’s 4-strand round casting machine like surface-borne crack and pit，and frequent breakout. As a result，the revamp proposal is made and implemented，which mainly includes measures like replacing the eccentric gear 4-bar linkage vibrating mechanism with an electric cylinder vibrator，and adding a mould electromagnetic stirring device. Thanks to the revamp，the after-revamp operation of the casting machine shows that the proportion of billets with surface cracks and pits is remarkably reduced，the breakout rate is decreased from 0.18% to 0.07%，and the billet central equiax crystal rate is obviously enhanced，which proves the correctness of the above mentioned technical revamp measures.