The utility model relates to a rail thermal treatment's test device, including the support, characterized by: the support is one section 1-1.2 meter and grows up to article rail section, and it has a recess that transversely link up to open at the top of support intermediate position. Its advantage is: can simulate the thermal treatment state of finished product rail through this test device, realize the rangette and smelt the test requirement of new steel grade on thermal treatment pilot scale line, guarantee for the industrialization trial -production of the new steel grade of thermal treatment provides the reliable experimental performance in earlier stage to the risk of effectively having avoidd industrialization trial -production.