"Double-edged old lady" refers to Du, a media creator. According to the inquiry of watermelon video, the double-edged old woman appeared in the works of Du, a watermelon video creator in the field of high-quality sports, a self-media creator who showed and explained traditional martial arts. The video introduces the eight-stage martial arts punch card which is mainly based on fitness and health preservation. In the works, there are traditional martial arts "sticking four doors" to explain and demonstrate, and traditional martial arts, using stick skills alternately from left to right, demonstrating the 75-year-old double-edged old lady. Watermelon video platform has 1 1.5 million fans.