The invention discloses a straightening process for a high-strength thin plate. The problem that the head of a steel plate collides with a straightening roll when the steel plate is bit in the large-rolling-reduction straightening process is avoided by adopting the method of firstly biting steel plate and then arranging roll bites. The problem that the steel plate cannot come in due to overlarge head-tail warpage amount in the subsequent straightening process is solved by positioning the head and tail of the steel plate in the straightening process. The straightness of the steel plate is improved through the straightening process of arranging the multi-pass progressive-decreasing type roll bits, and meanwhile the distribution of the internal stress of the steel plate is more uniform.