Outgoing Long-wave Radiation (OLR) is an important parameter in the study of precursor anomalies. OLR data contains important precursor information. Therefore, this study proposes a pre-seismic anomaly analysis method based on OLR data, the so called spatial-temporal analysis method. Then we apply the proposed method to analyze the Wenchuan earthquake on May 12, 2008, the Japan earthquake on March 11, 2011, and the Lushan earthquake on April 20, 2013. The experimental results show that there is important precursor information in OLR data. About three months before the occurrence of the three earthquake cases, the abnormal values in the epicenter area and its surrounding areas increased significantly, and the abnormal phenomenon in the surrounding area might be more obvious than the epicenter area. In addition, it is also found that before the occurrence of the three earthquakes, there were obvious peaks in the north direction anomaly curves in the studied areas. This finding is instructive for future work. Whether this rule is universal needs further verification.