An electronic yarn changing device for a circular knitting machine includes at least two driving units, at least two impelling plates respectively connected to the driving units, and at least two yarn feeding units. The impelling plates are impelled by the respective connected driving units to perform a one-dimensional motion. The yarn feeding units are arranged side by side, and are each provided sequentially with a yarn feeding plate, a yarn clamping plate, a mobile blade plate and a fixed blade plate. The yarn clamping plate includes a plurality of guide columns disposed correspondingly to the yarn feeding plate. The yarn feeding plates are respectively pushed by the corresponding impelling plates to perform a two-dimensional motion due to the plurality of guide columns. The mobile blade plates are also respectively pushed when the corresponding impelling plates perform the one-dimensional motion, and individually perform a one-dimensional motion once being pushed.