The invention relates to an electric thread pushing device of a bag sewing machine. The electric thread pushing device comprises a rotating electromagnet, a rotating arm, a connecting rod, a push cutter, guide wheels and a sensor, wherein the rotating electromagnet is arranged on a push cutter seat of the bag sewing machine, and is connected with the rotating arm, the push cutter is connected with the rotating arm through the connecting rod, the upper side and the lower side of the push cutter are provided with a plurality of guide wheels, the push cutter and a thread shearing groove of the bag sewing machine are positioned at the same height, the sensor is connected with the rotating electromagnet through electric signals, and is arranged under the bag sewing machine, the bag sewing machine starts to work for bag sewing, after the bag sewing is completed, the sensor senses whether a bag cover leaves away from the bag sewing machine or not, and if the bag cover leaves away from the bag sewing machine, a level signal is output to the rotating electromagnet, so that the rotating electromagnet clockwise rotates, and the push cutter is driven to push the tail of a bag sewing thread into the thread groove of the bag sewing machine for thread shearing action. The electric thread pushing device has the advantages that the structure is simple, the work is stable, the workload of operators for manually pushing the thread and shearing the thread is reduced, and the work efficiency is improved.