Abstract: Carbon nanotube（CNT）possesses favorable field emission characteristic. Studies indicate that carbon nanotube present along perpendicular orientation have better field emission competence than other orientation. In this paper, a method to make carbon nanotube present along perpendicular orientation on big area was depicted. Through testing relative parameters, we study improving field emission competence, as well as estimating field strength factor. This method is meaningful to deposit big screen field emission display（FED）.