A worm-type barrel-shroud bullet feeding structure of a toy gun and a bullet feeding mechanism thereof are provided. The bullet feeding mechanism includes a bullet storing case, a bullet feeding worm and a firing assembly; wherein, a bullet storing space and a bullet feeding channel arranged at an inner side of the bullet storing case and extended along the side are disposed in the bullet storing case, and the bullet feeding channel is in communication with the bullet storing space, the bullet feeding worm is disposed in the bullet feeding channel, and the firing assembly has an active shaft utilized for driving the bullet feeding worm to rotate, thereby allowing the bullet feeding worm to drive a bullet in the bullet storing case to be displaced towards a bullet feeding direction.