With the aim of reinforcing the soil in earthen ruins, anondestructiveinfrared imaging technique for studying soil conditions was explored. Thedisturbed soil samples of various physical conditions collected from the Jiaohe Ruins site were tested to determine the coefficient of thermal conductivity. Through analysis ofthe relationship between soil surface temperature and time,using unsteady state heat conduction theory, the coefficient of thermal conductivity of the soil was calculated. To verify reliability of this method, which measures coefficient of thermal conductivity of soil by an infrared imaging technique, the coefficient of thermal conductivity of the same soil was measured using thermal analyzer KD2 Pro.The difference between two test methods is small. This demonstrates the feasibility of measuring the coefficient of thermal conductivity of soil usingthe infrared imaging technique. The effect of different dry densities and moisture on the coefficient of thermal conductivity of the soil was studied. The results showed that if the dry density is increased, the coefficient of thermal conductivity of soil with constant water content is increased, too; if the water content is increased, coefficient of thermal conductivity of soil with a constant dry density is increased too.