The diffraction and absorption of UV light in SU-8 resist makes it very difficult to fabricate high precision microstructures with high aspect ratio in the process of UV LIGA,because the absorption coefficient gets bigger and the penetration depth gets shorter rapidly as the wavelength gets shorter.Therefore,such factors having effect on the precision of deep UV lithography as diffraction effect,exposure dosage,wavelength and distribution of fly's eyes lens etc.,are investigated in this paper.A method of correcting pattern transfer errors is developed through investigation of pattern transfer errors.Proposed method adopts the feature classification and area evaluation to modify the mask contour,thereby making the lithography contour as close as possible to the desired contour.In addition,it can be used to reduce the complexity and enhance the correction efficiency.