Comparing to the conventional boring head, the new type has the following advantages: 1, Guide by roller,with multi-point support and stable guide performance. 2,The point contact between the roller and the inner wall of the workpiece reduces the friction and pro-longs the using life; more importantly, it avoids the trouble of replacing frequently the guide pad. 3, The productivity can be increased by double. 4, The size can be adjusted in the range of 5 mm, it doesn't need replacing any parts, so the operation is very convenient and time-saving. The roller adopts the national standard, it is very easy to get at the reasonable price in the market, the using cost is low. The new type boring head is tested repeatedly, it has the stable performance and gains the good reputation from the user.