Bagasse was mechanically activated by a self-made stirring-type ball mill. The plant fibre-based cushion packaging material was prepared by using mechanically activated bagasse as raw material, cassava starch as adhesive, sodium bicarbonate, ammonium bicarbonate and ammonium bicarbonate compounded as foaming agents and talcum powder as filler. The effects of mechanical activation time, particle size of bagasse, and dosages of adhesive, foaming agent and filler on the performance of cushion packaging material were investigated by using static compression curve as evaluation index. The structure of cushion packaging material was also characterized by scanning electron microscopy (SEM). The results showed that mechanical activation can significantly enhance the compatibility among bagasse, adhesive and filler, which effectively improve the performance of cushion packaging material.