Swelling force is one of the important characteristics of the expansive rock. A method and experimental device for measuring the three-way swelling force of rock considering the effect of temperature are proposed. Based on the experimental design, the swelling force tests of black shale and red mudstone were carried out with this device, and the time history curves of the swelling force of the two kinds of rocks at different temperatures were obtained. The swelling force of black shale and red shale over time was analyzed, and compared with the swelling force of two kinds of rocks calculated based on the principle of elasticity, the influence of temperature on the swelling force of two kinds of rocks was further compared. The device has clear structure and simple operation, which is more conducive to students’ understanding of rock swelling force, and is also a supplement to the teaching content of rock mechanics experiment.