Abstract: In-situ application indicated that the two important problems of AGC were found: the roll eccentricity results in wrong roll gap adjustment that is provided by the gauge meter AGC; there is mutual interference when the monitor AGC is also used simultaneously as a monitor. The two problems are discussed in detail via the combination of the principle of AGC with its actual applications. For the problem evoked by roll eccentricity, a filtering technique is introduced to filter off the disturbance due to roll eccentricity and provide correct roll gap adjustment effectively. For the problem of mutual interference evoked by using monitor AGC simultaneously, the correlation between the two adjustments obtained in different ways is processed to avoid repeated or opposite adjustments. Application results indicated that the problems are thus solved well to meet the requirement for thickness control precision.