A method of producing variegated steel plate with multicoloured patterns, comprising the following process steps in sequence: A. preparing a steel strip to be printed; B. using a first roller coating unit to perform a first roller coating transfer on the steel strip to be printed; C. using a second roller coating unit to perform a second roller coating transfer on the steel strip to be printed after a specific time; in the step B, a servo control system is used to control said first roller coating unit, and the servo control system has a following control process: S1. data of diameter of each roller and a process speed of said first roller coating unit are input into a PLC control module, then the PLC control module calculates out theoretical roller surface linear velocity of each roller according to the process speed and the diameter of each roller, allows the theoretical roller surface linear velocity of each roller to be consistent with the process speed, and outputs the calculated theoretical roll surface linear velocity signal of each roller into a servo control module having an encoder; S2. the servo control module receives said theoretical roll surface linear velocity signal of each roller from the PLC control module and drives each roller according to the signal; S3. the encoder collects actual roller surface linear velocity of each roller and outputs the actual roller surface linear velocity signal of each roller into the PLC control module; S4. according to the received actual roller surface linear velocity signal and theoretical roller surface linear velocity signal of each roller, the PLC control module adjusts current frequency of electrical machine driving each roller, and adjusts the actual roller surface linear velocity of each roller to be consistent with the theoretical roller surface linear velocity of each roller, and then the roller coating transfer of the first roller coating unit is completed; characterized in that, in the sub-step S1 of step B, distance data between the first roller coating unit and the second roller coating unit is input into the PLC control module, and on the basis of the process speed and the distance data, the PLC control module calculates out a specific time to start the second roller coating unit, and starts the second roller coating unit according to the specific time, and then the second roller coating transfer of the second roller coating unit is completed; the roller coating transfer of the first roller coating unit and the second roller coating transfer of the second roller coating unit are used for printing multicoloured patterns on the steel strip to be printed. A. preparing a steel strip to be printed; B. using a first roller coating unit to perform a first roller coating transfer on the steel strip to be printed; C. using a second roller coating unit to perform a second roller coating transfer on the steel strip to be printed after a specific time; S1. data of diameter of each roller and a process speed of said first roller coating unit are input into a PLC control module, then the PLC control module calculates out theoretical roller surface linear velocity of each roller according to the process speed and the diameter of each roller, allows the theoretical roller surface linear velocity of each roller to be consistent with the process speed, and outputs the calculated theoretical roll surface linear velocity signal of each roller into a servo control module having an encoder; S2. the servo control module receives said theoretical roll surface linear velocity signal of each roller from the PLC control module and drives each roller according to the signal; S3. the encoder collects actual roller surface linear velocity of each roller and outputs the actual roller surface linear velocity signal of each roller into the PLC control module; S4. according to the received actual roller surface linear velocity signal and theoretical roller surface linear velocity signal of each roller, the PLC control module adjusts current frequency of electrical machine driving each roller, and adjusts the actual roller surface linear velocity of each roller to be consistent with the theoretical roller surface linear velocity of each roller, and then the roller coating transfer of the first roller coating unit is completed;