The present invention relates to a transmission mechanism for a side-moving inward-tilting window, each transmission mechanism group includes a fixed seat fixedly mounted on the window sash, a short connecting rod for tilting the window sash inward, a long connecting rod for opening the window sash and moving sideways, and a first locking device for locking or unlocking the short connecting rod, one end of the short connecting rod is hinged to the fixed seat, and the other end is hinged to one end of the long connecting rod, the other end of the long connecting rod is hinged to a first slider, a slide rail is fixedly mounted on the frame, the first slider is mounted on the slide rail and slides along the slide rail; one of the transmission mechanisms is provided with a first limiting device, the first limiting device includes a limiting connecting rod with one end hinged to the middle of the long connecting rod, a slide rod fixedly mounted on the short connecting rod, and a second locking device for locking the limiting connecting rod, the other end of the limiting connecting rod is provided with a first sliding groove matched with the slide rod, the slide rod is arranged in the first sliding groove and slides along the first sliding groove. The present invention limits the position of the window sash when tilting inward, avoids automatic closing, and plays a shockproof role.