0.1s。The residue blockage to the soil engaging parts is one of the key problems affecting the performances of no-till planter and other machine working in conservation tillage farming. Visual guidance system was studied to guide the machine working in between the stubble rows thus to solve the blockage problem in standing stubble conditions. The maize stubble rows were detected by image processing and the saturation of the field image was selected to segment the dry stubble and soil surface background. By comparing different methods of determining threshold, the iterative method was proved to be the most effective to segment the image automatically. The improved Hough transform was used to detect the inter-row line and the stubble row line to guide the machine. The experiments with large number of field images showed that the algorithm proposed can obtain the target navigation path rapidly within 0.1s and accurately for most conditions of standing stubble covered field. 