In this paper, on the basis of a theoretical analysis, we quantitatively explore the impact of urbanization on agricultural technical efficiency after measuring the agricultural technical efficiency and the urbanization level, from the perspective of different dimensions in 34 prefecture-level cities in Northeast China, using the SE-DEA model, entropy-TOPSIS method, and the panel regression model. The results show that, except for some cities that achieved technical efficiency in individual years, such as Yichun in 2012 (1.003), and Benxi in 2015 and 2016 (1.011 and 1.254, respectively), the overall level of agricultural technical efficiency in the Northeast Region is still relatively low. The level of overall urbanization in Liaoning was significantly higher than that in Heilongjiang and Jilin. The population urbanization and land urbanization levels of most cities were relatively high, but an obvious improvement trend was not observed. Some cities even appeared to undergo the phenomenon of “anti-urbanization”, and the economic urbanization showed an obvious characteristic of “high begins and low ends” in the Northeast. Moreover, except for the population urbanization, the overall urbanization, land urbanization, and economic urbanization all had a significant positive effect on the agricultural technical efficiency; the effect in Heilongjiang province was higher than that in Liaoning province, and Heilongjiang province showed an obvious catch-up trend. While enriching the research on urbanization and efficiency, this study provided political implications on strengthening the flow of factors between the urban and rural, improving the investment in technology and labor training, and improving the compensation mechanism.