An operation device of a multi-pole miniature circuit breaker, comprising a handle pivotally mounted on a circuit breaker housing through a rotating shaft, a rotary plate pivotally mounted on the circuit breaker housing through a mandrel,two static contacts (22, 27) and two movable contacts (18, 38) capable of performing closing/breaking fit with the static contacts (22, 27) respectively, an energy storage spring acting on the rotary plate and a resetting member configured to drive a tripping rod to reset; and two electromagnetic tripping devices arranged side by side, each electromagnetic tripping device comprising an actuating ejection rod which is capable of providing a short-circuit tripping action when a short-circuit current appears; wherein, the operation device further comprises: a tripping connecting rod which is pivotally mounted on the rotary plate through a first twisting shaft; a tripping rod which is provided with a lock tooth, a control element capable of being matched with electromagnetic tripping devices of circuit breakers of two adjacent poles; a U-shaped rod of which the two ends are in joint connection with the handle and the tripping connecting rod respectively, and which can drive the tripping connecting rod to move anticlockwise or clockwise about the first twisting shaft; characterized in that; the tripping connecting rod is provided with a hook, and in that the operation device further comprises: two thermal tripping devices arranged side by side, each thermal tripping device comprising a bimetal sheet which is capable of providing an overload tripping action when an overload current appears; an actuating rod capable of being matched with bimetallic sheets of thermal tripping devices of the adjacent two-pole circuit breaker, the tripping rod being pivotally mounted on the rotary plate through a second twisting shaft and being capable of doing a finite rotation about the second twisting shaft; two short-circuit short columns (31, 32) arranged on the control element of the tripping rod side by side, the two short-circuit short columns (31, 32) being matched with actuating ejection rods (24, 24) of the two electromagnetic tripping devices in a triggering manner respectively; two overload short columns (29 and 30) arranged on the actuating rod of the tripping rod side by side, the two overload short columns (29 and 30) being matched with the bimetallic sheets (21,21) of the two thermal tripping devices in a triggering manner respectively. a tripping connecting rod which is pivotally mounted on the rotary plate through a first twisting shaft; a tripping rod which is provided with a lock tooth, a control element capable of being matched with electromagnetic tripping devices of circuit breakers of two adjacent poles; a U-shaped rod of which the two ends are in joint connection with the handle and the tripping connecting rod respectively, and which can drive the tripping connecting rod to move anticlockwise or clockwise about the first twisting shaft; characterized in that; the tripping connecting rod is provided with a hook, and in that the operation device further comprises: two thermal tripping devices arranged side by side, each thermal tripping device comprising a bimetal sheet which is capable of providing an overload tripping action when an overload current appears; an actuating rod capable of being matched with bimetallic sheets of thermal tripping devices of the adjacent two-pole circuit breaker, the tripping rod being pivotally mounted on the rotary plate through a second twisting shaft and being capable of doing a finite rotation about the second twisting shaft; two short-circuit short columns (31, 32) arranged on the control element of the tripping rod side by side, the two short-circuit short columns (31, 32) being matched with actuating ejection rods (24, 24) of the two electromagnetic tripping devices in a triggering manner respectively; two overload short columns (29 and 30) arranged on the actuating rod of the tripping rod side by side, the two overload short columns (29 and 30) being matched with the bimetallic sheets (21,21) of the two thermal tripping devices in a triggering manner respectively. two thermal tripping devices arranged side by side, each thermal tripping device comprising a bimetal sheet which is capable of providing an overload tripping action when an overload current appears; an actuating rod capable of being matched with bimetallic sheets of thermal tripping devices of the adjacent two-pole circuit breaker, the tripping rod being pivotally mounted on the rotary plate through a second twisting shaft and being capable of doing a finite rotation about the second twisting shaft; two short-circuit short columns (31, 32) arranged on the control element of the tripping rod side by side, the two short-circuit short columns (31, 32) being matched with actuating ejection rods (24, 24) of the two electromagnetic tripping devices in a triggering manner respectively; two overload short columns (29 and 30) arranged on the actuating rod of the tripping rod side by side, the two overload short columns (29 and 30) being matched with the bimetallic sheets (21,21) of the two thermal tripping devices in a triggering manner respectively.