The invention relates to the technical field of steel rolling processes, in particular to a fault machine halt control method of a section steel rolling mill. The invention provides the fault machine halt control method of the section steel rolling mill by aiming at the defect that the waste steel quantity is increased because of the immediate machine halt once the rolling mill has the fault in the traditional steel rolling process. The invention has the main technical scheme that the method comprises the following steps: detecting the fault types; carrying out different processing according to the fault types; adopting the immediate machine halt measures for fatal faults; and stopping steel feeding instead of adopting the immediate machine halt measures for non-fatal faults, and carrying out machine halt after the rolling of all rolled elements on the rolling line is completed. The loss caused by the frequent machine halt can be reduced, and the invention is applicable to the steel rolling process.