Consumption is both an economic activity and social behavior. Therefore, the consumption of migrant workers in the city plays an important role in their urbanization and urban economic growth. This paper employs OLS regression model and quantile regression method to take an empirical test of the impact of the pension insurance system on the consumption of rural migrant workers in the city. The results show that in terms of the mean value, pension insurance can improve the consumer identity of migrant workers and increase their consumption spending. Also, their consumer identity has an intermediate effect and can enhance the positive impact of the pension insurance on consumption expenditure. At different quantiles, the consumption effects of pension insurance are different. At lower quantiles, pension insurance can promote the consumption of migrant workers and consumer identity has an intermediate effect. But at a relatively high quantile, pension insurance has only insignificant effect on consumption. Migrant workers on lower consumption levels have smaller premium burden and therefore have stronger desires to get insured. Thus, pension insurance plays a remarkable role in promoting their consumption. The paper suggests deepening the reform of the household registration and pension insurance system, increasing the number of migrant workers getting insured and meanwhile lowering the threshold for them to draw security deposits.