The invention discloses an inserting-pin type automatic loading device for ranking tobacco leaves. The automatic loading device comprises a wallboard, wherein a front conveying belt for conveying horizontally stacked tobacco leaves and a rear conveying belt for conveying the tobacco leaves which are stripped into single-stem tobacco leaves are sequentially arranged on the surface of the wallboard; a drive plate inserting pin mechanism, which is used for stripping the conveyed stacked and staggered tobacco leaves into the single-stem tobacco leaves, is arranged between the front conveying belt and the rear conveying belt; the drive plate inserting pin mechanism comprises a fixed cam and a rotary disc which sleeves the outer ring of the cam and rotates around the cam; and an inserting pin, which radially stretches out of the surface of the rotary disc outer ring and is inserted into stacked tobacco stems and which is rotated along with the rotary disc so as to strip the tobacco stems under the ejecting action of a cam track when the rotary disc is rotated, is arranged between a rotary disc inner ring and the cam. According to the automatic loading device provided by the invention, the inserting pin in the drive plate inserting pin mechanism can stretch and rotate along with the rotary disc so as to strip the stacked and staggered tobacco stems into a single-stem state, so that the efficiency of cranking work and the consistency of cranking quality are improved.