The invention provides a transmission mechanism with an adjustable initial position and a circuit breaker using the same, and relates to the technical field of high-voltage switches. The transmissionmechanism comprises a closing resistor, a drive mechanism connected with the movable end of the closing resistor. The drive mechanism connected with the movable end of the closing resistor includes abracket, a first connecting member and a second connecting member, wherein the first connecting member and the second connecting member are hinged by a shaft sleeve, the shaft sleeve has an eccentricconnecting hole, and the first connecting member and the shaft sleeve are in check fit, the second connecting member and the shaft sleeve are in running fit, the relative position of the first connecting member and the shaft sleeve is adjustable, wherein one of the first and second connecting members is a contact pull rod that is mounted on the bracket in a direction perpendicular to the extendingdirection of the shaft sleeve. Through the check fit and the adjustable relative position between the first connecting member and the eccentric connecting hole, the initial position of the contact pull rod can be finely adjusted, and thus the pre-switching time of the resistor can be adjusted. The transmission mechanism is simple in structure, and convenient to adjust.