Predicting the focal plane is an effective method to increase the scanning speed of an automatic microscopy system. However, the image easily defocuses when using traditional predictive scanning methods. In this paper, we introduce an adaptive predictive scanning method (APSM) that greatly improves the accuracy of predictive scanning. Instead of using a fixed planar model to predict the focal plane position, APSM updates the predicted focal plane in real time based on the focal position of the reference point during the scanning process, thus predicting the focal position of each local view more accurately. Using the APSM, the average image defocus value is 0.39 μm, while conventional predictive scanning methods reach 1.05 μm. APSM greatly improves focal accuracy and can be applied to a high-precision automatic microscopy system.