The utility model relates to an experimental device for evaluating damage of stratum rock core and the experimental device for evaluating the damage of the stratum rock core is special for exploration and development of oil and gas fields and is mainly composed of an air source, a high-pressure reducing valve, a mud tank, a mud pump, a multi-point core clamping unit with a circulatory end face, a liquid flowmeter, a pressure sensor, a ring pressure pump, a return pressure controller and a data acquisition unit, wherein the return pressure controller is connected with a valve through a pipeline, and the data acquisition unit is connected with all components with electronic induction or control and a computer. The experimental device for evaluating the damage of the stratum rock core further comprises a rock core gaseous phase permeability measuring system which is composed of a high-pressure air source, a gas humidifier, a gas dryer and a gas flowmeter. The experimental device for evaluating the damage of the stratum rock core is capable of imitating a rock core gaseous phase permeability measuring experiment, a liquid phase permeability measuring experiment and a drilling fluid circulating pollution experiment under conditions of various temperature and pressure and evaluating degree of the damage of the stratum rock core, simple and convenient to operate, automatic in data acquisition, high in accuracy, and capable of providing reliable data for the exploration and development of the oil and gas fields.