Abstract:The basic dimensional tolerance of unconfined compressive strength test mould for highway engineering test is not clear, and there is no technical index basis for calibration and measurement confirmation. Through the in-depth interpretation of JTG E51-2009 《 Test Rules for Stabilized Materials of Inorganic Binders in Highway Engineering 》, this paper indirectly gives the basic dimensional tolerance of unconfined compressive strength test, and gives the calibration measuring instruments and calibration methods according to the dimensional tolerance. Finally, it gives the measurement uncertainty analysis process of calibrating the basic dimensions of unconfined compressive strength test by this method, which proves the feasibility of this method.