The invention relates to the technical field of cement stabilized macadam paving engineering, in particular to an experimental device for the inner temperature and humidity of cement stabilized macadam test pieces. The experimental device comprises a bracket, a plurality of clamps and a plurality of test piece maintenance covers, wherein the clamps and the test piece maintenance covers are arranged on the bracket, and the test piece maintenance covers are arranged outside the clamps and are driven by maintenance cover driving devices to move up and down. The test pieces are arranged on the clamps. The test piece maintenance covers are internally provided with refrigerating pieces, heating pieces, humidifier spraying pipes and outer cover inner temperature and humidity sensors. A circuit board, a power supply and a humidifier are also arranged above the bracket. Test piece inner temperature and humidity sensors are arranged in the test pieces and penetrate through test piece sealing plugs connected with the test pieces. The inner temperature and humidity of the test pieces can be measured in the maintenance state and the natural state to form a plurality of groups of comparative tests, so that the experimental effect is better, and the accuracy of data can be better reflected.