Background: In recent years, the widening gap of health service utilization between different groups in mainland China has become an important issue that cannot be avoided. Yet the related study on the health services utilization for older rural-to-urban migrant workers and comparative study on older rural-to-urban migrants in China is still in its infancy. Our study explored the health service utilization of the older rural-to-urban migrant workers based on a sinicization of the latest Andersen model, by comparison with the older rural dwellers. Further, our study revealed the facets and causes by decomposing the differences in the health service utilization into determinants.Methods: The data of China Labor-Force Dynamic Survey in 2016, the data of Urban Statistical Yearbook in 2016, and Statistical Bulletin were used. Our study applied the lasted Andersen Model according to China's currency situation. Before we studied the health service utilization, we used Coarsened Exact Matching to control the confounding factors to enhance the comparability of the two groups. The matched data were used to analyze the influencing factors. Fairlie decomposition method was used to analyze the differences and the sources of health service utilization between older rural-to-urban migrant workers and their rural counterparts.Results: After matching, the probability of two weeks outpatient of older rural-to-urban migrant workers (5.59%) was significantly lower than older rural dwellers (7.57%). The probability of inpatient of older rural migrant workers (5.59%) was significantly lower than older rural dwellers (9.07%). 17.98% of the total difference of two weeks outpatient utilization was due to the observed influence factors. 71.88% of the total difference of inpatient utilization was due to the observed influence factors. Income quantiles (49.57%), self-assessed health (80.91%), and sex ratio in the community (-102.29%) were significant in the differences of inpatient utilization.Conclusions: The findings have important implications for the difference in the health services utilization between older rural-to-urban migrant workers and older rural residents in China, urging the government to take full account of the heterogeneity. The results provide references for the healthcare policy reform in the process of active ageing in China.