Fracture energy, which reflects the split property of brittle materials, is a significant parameter. For present tests of measuring it, the indirect test itself has insuperable disadvantage, while the direct tension test, in spite of an ideal way, is too limited to be widely applied in ordinary labs for its over high requirement for the test machine. The paper analyzed the disadvantage of the direct tension machine and improved it: a new elastic foundation of lower clamper replaced the original rigid one. Using the improved machine, the complete stress-strain tensile curve of the brittle materials was obtained easily. Further, the fracture energy could be calculated. Basing on studies, the paper recommended it may as well to get the fracture energy by improved direct tension machine.