The invention provides an isothermal adsorption and desorption system for raw coal. The isothermal adsorption and desorption system comprises a test cabinet and a control cabinet, the test cabinet is provided with an adsorption testing device, a vacuumizing device and a hydraulic device, the control cabinet is located on the side portion of the test cabinet, and the control cabinet is provided with a control computer; the adsorption testing device comprises a plurality of experiment cylinders, each experiment cylinder comprises a sample cylinder and a sealing bolt, the top face of each sample cylinder is fixedly connected with a circular upper top plate, the circle center of each upper top plate is vertically provided with an upper connection hole communicated with the inside of the corresponding sample cylinder, the bottom face of each sample cylinder is fixedly connected with a circular lower bottom plate, the center of each lower bottom plate is provided with a lower connection hole communicated with the inside of the corresponding sample cylinder, the inner wall of each lower connection hole is provided with an inner thread, and the upper surface of each lower bottom plate is provided with a vertical rod in the vertical direction. The isothermal adsorption and desorption system is reasonable in design, and the control computer controls the adsorption testing device, the vacuumizing device and the hydraulic device to operate through a control wire to simulate isothermal desorption and adsorption of raw coal in different environments and draws adsorption and desorption curves.