The invention discloses a secondary circuit fast-switching operation mechanism of a current transformer, and relates to the field of current transformers of transformer substations. a secondary circuit switching operation part of an existing current transformer adopts a bolt structure, has complex operation, has no interlocking function and is prone to maloperation danger. The mechanism includes abase, a two-way switching disconnecting link, a disconnecting link connecting static contact for connecting a secondary circuit of the current transformer, a protective static contact and a current secondary circuit short circuit grounding static contact, wherein the protective static contact and the current secondary circuit short circuit grounding static contact are arranged on the left and right sides of the disconnecting link connecting static contact respectively and used for collecting and protecting the secondary current circuit; the two-way switching disconnecting link is connected with the disconnecting link connecting static contact, and can rotate in the right and left directions to achieve switching on of different static contacts; interlocking lock catch is arranged between the two-way switching disconnecting link and the base, and when the two-way switching disconnecting link is switched to be in contact with the protective static contact for switching on, the lock catchis locked to make a switching operation handle pulled off by maloperation. The secondary circuit fast-switching operation mechanism of the current transformer can avoid open circuit accidents of thecurrent secondary circuit and improve the circuit switching efficiency.