With optical micro scanning technology, the spatial resolution of micro thermal imaging systems can be improved without changing the detector structure. But in order to obtain high-quality oversampled reconstructed image, the micro scanning position must be calibrated. A each point adaptive calibration micro scanning method based on the zero calibration theory is proposed. The reconstruction contrast experiments of undersampled microscopic thermal images are done before and after calibration with the thermal image and the real thermal microscopic image. The experimental results show that the method significantly improves the oversampled reconstructed image quality, and enhances the system spatial resolution. This method can also be used in other electro-optical imaging systems.