The invention discloses an automatic-replacement inner-layer-ejecting child garment. The automatic-replacement inner-layer-ejecting child garment comprises a jacket. An outer layer is arranged on theback face of the jacket, a first sweat-absorbing inner layer and a second sweat-absorbing inner layer are arranged in the outer layer and arranged on a ball screw, the ball screw is arranged on the inner side of the outer layer, and the two ends of the ball screw are fixed onto the outer layer; a fixed nut and a movable nut are arranged at the upper end of the first sweat-absorbing inner layer, the fixed nut is fixedly arranged on one side of the ball screw, and the movable nut sleeves the ball screw; a pulling rope is fixedly arranged at the bottom of the first sweat-absorbing inner layer, awinding wheel is also arranged on the movable nut, the other end of the pulling rope is wound through the winding wheel, and a storage cavity for storing the second sweat-absorbing inner layer is alsoarranged on one side of the outer layer. The automatic-replacement inner-layer-ejecting child garment has the advantages that when a child runs for a long time, the first sweat-absorbing inner layeris wetted by sweat, automatically folded, taken out and replaced with the second sweat-absorbing inner layer, and the first sweat-absorbing inner layer is externally arranged and dried with air.