Abstract: In plate width control process, a micro-reducing rolling technique was put forward to improve the square degree on different broadening ratio of products. The width alteration rules on different broadening ratio as well as the relationship between lateral flow factors and broadening coefficient were analyzed. The width form functions were built, each point dog-bone recovery broadening along length direction was calculated, and the reducing width rolling curve with edger roll gradual gap based on this recovery broadening was obtained. Practical applications showed that the method proposed is available to improve greatly the product rolling yields and worthy to apply to plate rolling.