The gamma retest of the old well in the oil hole is an economical and practical method to measure the radioactivity by FD-3019 probe tube when the oil well maintenance team takes out the sucker rod. Due to the influence of cementing cement ring in oil drilling on gamma logging results, the current gamma logging code has only the correction of molten iron coefficient but no correction of absorption attenuation of cement ring. Therefore, gamma reiteration data can be used to appraise drill radioactive anomaly correctly through the cement ring attribute parameter correction. It is concluded that the main influence parameters of cementing cement ring are cement ring density and cement ring thickness. By making a number of cement ring model holes with different thickness and density, simulating down hole conditions, establishing models and using different model cement ring absorption coefficient values, the authors finally found out the influence coefficient of cementing cement ring on gamma logging illumination rate and carried out correction and demonstration experiments to make the revised data infinitely close to the true formation value. Combined with the actual data of an oil field block in Inner Mongolia, the authors revised the data through the modified coefficient of cement ring experimental logging and discussed the relationship between the density, thickness of cement ring and the irradiation rate. The feasibility of the method is validated by verifying hole technology. The result provides the correction basis for guiding the results of the next re-survey of old oil wells.