Steel rail cross section specification full-length fluctuation control method

The invention discloses a steel rail cross section specification full-length fluctuation control method. The method comprises obtaining the distribution length l of the full-length fluctuation abnormal part of each dimension of the cross section on a steel rail and the mean deviation of all dimension fluctuations of the cross section according to the steel rail cross section dimension detection curve under the normal steel rail rolling condition, determining the compensation part on the steel rail cross section, and determining the compensation value of a rolling part corresponding to the compensation part; selecting a compensation rolling mill and a compensation pass according to the rolling part and the compensation value, and determining the compensation amount of the compensation pass; determining to-be-compensated length L and compensating for the to-be-compensated length L of the steel rail during rolling; and when the to-be-compensated length L is reached, allowing the roll gap S at the rolling part on the compensation rolling mill to restore to the normal roll gap s, and allowing the displacement value Y to restore to the normal displacement value y. The method provided by the invention effectively controls steel rail cross section specification full-length fluctuation, reduces rolling deviation, requires no additional equipment and is mainly used for steel rail rolling control.