Abstract: Research progress of GPS, machine vision and multi-sensor fusion technologies applied in automatic guidance was analyzed in this paper. GPS has the advantage of high accuracy. Machine vision can acquire affluent environment information. Sensor fusion using different sensors to form high accuracy and high reliability navigation strategy can combine both advantages of GPS and machine vision. However, the accuracy and reliability of GPS are easily affected by environmental factors. Vision processing in machine vision guidance is greatly interfered by natural light, etc.. Furthermore, vision arithmetic is not fast enough. For sensor fusion, there are still some problems when concerning about sensor precision, information acquirement, data processing speed and capability of anti-disturbance, etc.. Solving the above problems will promote the application of automatic navigation in agricultural engineering.