Abstract: Single crystal germanium (Ge) is the key material for manufacturing infrared lens and windows, which are widely used in laser detection and satellite remote sensing. To achieve high-quality and highly efficient lapping of Ge, the fixed abrasive lapping method is employed, and the surface roughness and material removal rate of Ge are taken as evaluation indexes. Through single factor experiment and orthogonal experiment, the influence of abrasive particle size of lapping pad and parameters (speed of lapping disc, lapping pressure and time) on the characteristics of fixed abrasive grinding is studied. The results show both the surface quality and machining efficiency of Ge can be improved by using diamond lapping pad with abrasive particle size of W8-12. The effect of lapping parameters on the surface roughness of Ge is relatively small, the order of significant factors affecting the removal rate of Ge is speed >lapping time >lapping pressure. The best lapping parameters for the material removal rate include a lapping disc speed of 80 r/min, a lapping pressure of 9 kPa, and lapping time of 4 minutes. Response surface analysis shows the interaction between the rotating speed of the lapping disc and the lapping pressure exerts a great influence on the material removal rate. The study provides guidance for the selection of process parameters in grinding single crystal germanium.