Abstract: This paper presented the necessity of electrical control device of 2 m explosion-proof cycloconverter winch on the basis of analysis of the present situation of 2 m explosion-proof winch. The working principle of cycloconverter was described briefly. For the key technology of 2 m explosion-proof winch, a method of two-variable control theory was put out, and the full scope speed adjustment was solved by combining cycloconverter with speed and voltage adjustment. Therefore, a speed adjustment system of full open loop, non-circulation and non-dead time was achieved. Finally, the implementation method of this system was given.