The invention discloses an internal rotation coal cutting method of a thin coal seam roller coal cutter, which is most suitable for mining extremely unstable thin coal seams. An internal rotation coal cutting mode of the roller coal cutter can be obtained by reversely arranging the left and right rollers on a rocker arm of the conventional coal cutter and connecting any two phases in a three-electric phase sequence in a cutting motor wiring cavity of the roller coal cutter in a replaceable mode. In the coal rock mining process of the extremely unstable thin coal seam, the original cutting from the coal seam to rock strata of the rollers of the roller coal cutter is changed into the cutting from the rock strata to the coal seam, so that dust can be effectively reduced; a working environment is improved; material categories are increased; the recovery rate of cleaned coal is improved; body vibration is reduced; equipment failure rate is reduced; and mining efficiency is improved. The method is simple, and convenient to operate and has a good using effect, coal mining speed is improved, and labor intensity is reduced.