Abstract: A multi−targets X−ray microscope system based on SEM is established and its imaging performance is analyzed in this paper. The modified X−ray imaging system can produce adjustable low-energy X−ray by switching different targets, which can be used to obtain high–resolution and high−contrast images for light samples. Based on the existing platform, aluminum, chromium and tungsten were tested as target material separately, and then take DR (Digital Radiography) images for a poplar leaf together with an ant sample. Results show that aluminum target provides the best quality in contrast when a sample is thin (～100 μm) or with shape edge areas. However, chromium and tungsten target can get better contrast when the sample is thick (～1 mm) and overlapped.