There is a hard knot on the bottom of the foot like a callus that hurts to walk, and the possible causes are callus on the bottom of the foot, corns, metatarsal warts and so on. 1. callus on the soles of the feet: may be long-term friction, pressure, induced by the skin cuticle overgrowth caused by callus on the soles of the feet, appearing on the soles of the feet have a hard knot like a callus walking pain phenomenon. 2. Chicken eye: Chicken eye may be due to long-term wearing high heels standing or walking, increase the foot pressure and friction caused by the foot, there may be a hard knot on the sole of the foot like a callus walking pain phenomenon. 3. metatarsal warts: metatarsal warts may be caused by human papilloma virus infection, which can occur on the sole of the foot at the place of pressure, forming a hard knot like a callus, and painful symptoms when walking. The bottom of the foot has a hard knot like callus walking pain may also have other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.