Abstract: Hightemperature gas-cooled reactor and the drive mechanisms which can be used were summarized. The principle and design requirements of electromagnet drive mechanism were emphasized. The empirical formula calculation method and ANSYS software were exploited to design the coil of the electromagnet. Model experiment was carried on to examine the reliability of the two methods. Finally the ampere-turns of coil which can meet the requirement of electromagnetic forces were obtained through ANSYS method and the electromagnetic force performance curve in the start-up procedure was obtained.