This paper introduces AC variable-speed driving control technology application in the continuous annealing line,including the drive system configuration,the driving control characteristics of CAL and the main control functions of the drive system.Firstly introduces the main process of the continuous annealing line,the features of the 6SE70 series common DC bus drive system and the G150 series drive system. Secondly,for the continuous annealing line,there are more strict requirements for the continuity of production and more special requirements for the drive control characteristics.We do a lot of improvement and standardization for the driving control functions and the interfaces of the line automation control system. This paper discusses the communication interface specifications and the dimension transformation methods between the drive and the basic automation system.The detail dimension transformation methods and calculation method about the line speed setting and the actual roller dimension setting are given,and detail description for the calculation method of the reference speed in the drive.Article also emphasized illustrates realizing and testing methods of inertia compensation of equipment in the drives,and standardize the value of line accelerate and decelerate rate,and the inertia test method and inertia compensation coefficient calculation method is introduced in this paper.For the bridge rollers and furnace help rollers load balance control,this paper presents two different load balance control strategies,the load balance control principle for bridge rollers which data communicates from main station to slave stations by Simolink,and the load balance control principle for furnace help rollers which use droop control.The different characteristics of those two methods are stated in detail. This paper introduces AC variable-speed driving control technology application in the continuous annealing line, including the drive system configuration, the driving control characteristics of CAL and the main control functions of the drive system. First primarily introduced the main process of the continuous annealing line, the features of the 6SE70 series common DC bus drive system and the G150 series drive system. Secondary, for the continuous annealing line, there are more strict requirements for the continuity of production and more special requirements for the drive control characteristics. We do a lot of improvement and standardization for the driving control functions and the interfaces of the line automation control system. This paper discusses the communication interface specifications and the dimension transformation methods between the drive and the basic automation system. line speed setting and the actual roller dimension setting are given, and detail description for the calculation method of the reference speed in the drive. Article also found in testing of inertia compensation of equipment in the drives, and standardize the value of line accelerate and decelerate rate, and the inertia test method and inertia compensation coefficient calculation method is introduced in this paper. For the bridge rollers and furnace help rollers load balance control, this paper presents two different load balance control strategies, the load balance control principle for bridge rollers which data communicates from from main station to slave stations by Simolink, and the load balance control principle for furnace help rollers which use droop control. the different characteristics of those two methods are stated in detail.