The quick action mode and switching-off principle of the DC short-circuit current limiter is the same. It would be switched off before the instantaneous current of short-circuit current gets to the expected current limiting value. The actual maximum instantaneous value of short-circuit current is far lower than the first half-wave peak value of short-circuit current. It provides an economical and reasonable short-circuit current solution for DC users of the power systems. The differences between it and the traditional AC products are: (1) sensors; (2) electronic controller; (3) fuse. The products have been successfully applied to Wenchang submarine cable repair project, CNOOC direct current transmission project, Guizhou distribution network project, etc., and have won unanimous favorable comments from customers.