A method that imaged directly to sloping edge was used to get the modulation transfer function of fiber optic taper coupled with CCD. It used static edge that was tilted slightly with respect to the columns of fibre to achieve different value of different row. This method replaced scanning in conventional test and it was not necessary to ensure that edge was parallel strictly to array .Thus mechanical error was deduced accordingly. In data processing adopting two averages including different position of one image and multi-measurement result .This processing avoided the influence of non-isoplanantic result from dispersancy to a certain extent.