In order to improve the manufacturing precision of nanoscale germanium, nano-scratch instrument was used to process the nanogrooves of single crystal germanium. The morphology of the groove was observed by scanning electron microscope, and the three-dimensional morphology was measured by the three-dimensional white light interferometer. The effect of the cutting speed, the applied vertical load and scratching number on the morphology of single crystal germanium nanogrooves was studied. Linear fitting curves and power function fitting curves of vertical load and number of scratches with groove depth and width were established and analyzed. The results show that the width and depth of single crystal germanium nanogrooves are very small with the cutting speed, and with the increase of vertical load, the scratching number increases. The fitting degree of the curve is very high. It can predict the depth and width of the nanoscale groove more accurately, which can reduce the surface roughness of the workpiece and improve the surface quality of the workpiece.