Abstract: In order to analyze the range and damage of locusts plague that occurred in New South Wales, Australia, 2010, the author used MODIS/Terra date from 2008 to 2010 to judge the vegetation growth in 2010 through △NDVI value image, which were the different NDVI images of before and after vegetation growing period. The results showed that: from an overall perspective, the detected damage and actual range were basically the same, which could reflect the disaster situation in New South Wales; the undamaged area was almost 410,000 km²; the light damaged area was about 50,000 km²; the seriously damaged area was about 340,000 km²; the total damaged area was about 390,000 km², which accounted for 49% of the total area. Compared to the official statistics, the relative error of damaged area was about 22%, the reasons were the lack of pixels and some wrong pixels, and the missing pixels could not be included in the calculation of the damaged area and reduced the precision of damage situation classification. This method could be used to study the range and damage of locusts plague.