A bicycle gear shift control system capable of avoiding frequent gear shifting includes: a power module; a microcomputer electrically connected to the power module for allowing a cyclist to switch between the automatic gear shifting mode and a manual gear shifting mode; a gear shifting driver electrically connected to the microcomputer, substantially connected to a derailleur, and instructed by the microcomputer to drive the derailleur to perform gear shift control; and a manual shifting controller electrically connected to the microcomputer. The microcomputer has an automatic gear shifting logic whereby the microcomputer determines the timing of automatic gear shifting and performs gear shifting. The microcomputer further has a gear shifting delay logic that involves delaying for a delay time interval from commencement of gear shifting according to a gear shifting criterion and ruling out all other gear shifting commands during the delay time interval.