The present invention discloses a moving contact linkage structure of modular circuit breaker. The moving contact linkage structure of modular circuit breaker comprises: a first case having a first mounting hole and the second case having a second mounting hole, the first mounting hole and the second mounting hole corresponding to each other on position; a first shaft; an operation mechanism side plate having a third through hole, the third through hole being positioned at a rotation center of a contact rotor; an operation mechanism lower connecting rod having a fourth through hole, the first shaft connecting to the fourth through hole; a contact rotor being rotatable around a rotation center, the contact rotor having mating surfaces on both sides; a first linkage member connecting to the mating surface on a first side of the contact rotor; a second linkage member connecting to the mating surface on a second side of the contact rotor; the contact rotor, the first linkage member and the second linkage member being mounted in the first mounting hole and the second mounting hole.