A hybrid diffractive/refractive achromatized telecentric f-θ lens system had been designed with a hybrid diffractive/refractive lens and three refractive lenses. The entrance pupil was placed at the focal plane so that it was a telecentric system. Contrast to the US patent 4,925,279, the lateral color reduced by one-orderinmagnitude(from2.40mmto0.23mm), andthemaximaltransverseaberrationreducedfrom260μm、1350 μm、2090 μm to 5 μm、250 μm、318 μm for 0°、14° and 20° field of views, and the maximal field curvature reduced from 8 mm、10 mm、13 mm to 0.5 mm、1 mm、6 mm for the aforementioned field of views. The designed f-θ lens system could be applied in color scanning systems, such as color laser printers and color digital photo printers. It could also be applied in high energy scanning systems. When applying the designed hybrid diffractive/refractive achromatized telecentric f-θ lens system to the high energy scanning system, a big laser machine operating in one longitudinal mode could be replaced by a small multi-mode operating laser machine,and the system could be simplified greatly and the accuracy could be proved.