The electric permanent-magnetic chuck is the new type magnetic chuck making use of electric pulse for "switching on and switching off" magnetic force. After holding work piece with magnetic force, this chuck will keep the attraction indefinitely. The time need for "On/Off" is less than 1 second. The energy consumption of electric pulse is very small, so the chuck will not be heated and distorted. The electric permanent-magnetic chuck is without mechanical moving components, so it is with stable & hard structure and high precision. Switching on and off with electric pulse in convenient automatic control. The electric permanent-magnetic chuck can be widely used as holding component of various kinds of plain surface grinder and electro machining machine tools. The high power electric permanent-magnetic chuck can also be used for holding work piece for milling machine, drill press, planning machine and boring lathe. Furthermore, it is also adopted in the machining center and FMS system as attached fixture device. Fine-pole magnetizing sheets and magnetizing blocks in various kinds of specification s are the auxiliary tools of ordinary rectangular chuck, which can be used for solving problems of ordinary chuck on holding thin & small work piece or work piece with special shapes, they are the effective auxiliary tools for extending application scope of ordinary magnetic chuck.