A telescoping control mechanism for controlling a medical instrument, the medical instrument includes a telescoping axis which intersects a patient at a work point, the telescoping control mechanism includes: a first rotary module disposed on a base, and including a first axis which extends through the work point； a second rotary module disposed on the base and including a second pivot which is pivoted to the base and has a second axis perpendicular to the first axis； a linkage module including a proximal linkage assembly disposed on the second pivot and parallel to the telescoping axis, and a distal linkage assembly for mounting of the medical instrument； and a telescoping module disposed on the proximal linkage assembly to drive the distal linkage assembly to reciprocate along the proximal linkage assembly, which consequently causes movements of the medical instrument along the telescoping axis.
