The use of multi-wheel straightening method, the same service control cut off, can guarantee the accuracy of the cut off in the state of high-speed movement, polishing machine operation is the key to try to get the maximum polishing rate, in order to remove the damage layer generated when grinding as soon as possible. At the same time also to make polishing damage layer will not affect the final observed organization, that is, will not cause false organization, to achieve polishing straightening consistent synchronization.