A minimally invasive ultrasonic cutter head and a minimally invasive ultrasonic powered system for bone; the minimally invasive ultrasonic cutter head comprises an cutter rod (11, 21, 31, 41, 51, 61) and a head end (12, 22, 32, 42, 52, 62), the head end (12, 22, 32, 42, 52, 62) being located at a front end of the cutter rod (11, 21, 31, 41, 51, 61), and the head end (12, 22, 32, 42, 52, 62) being bent laterally at a certain angle, wherein knurled teeth or skewed teeth are provided on the bent portion. By means of bending the head end (12, 22, 32, 42, 52, 62), bone tissue around the intervertebral foramen may be removed. Therefore, a surgeon may, as much as possible, have more operation space under the limited foramen channel, thereby increasing bone removal efficiency.