Autonomous vehicles are a double-edged sword, bringing happiness and convenience to peoples lives but also silently creating various crises and bad effects. The purpose of this article is to explore and analyze the implications of autonomous vehicles, with a focus on their impact on cities, as they are and will be massively linked to smart city systems and operate on urban roads. In this paper, the author has analyzed the findings and data from many past literature and research sources and summarized them based on his own research and ideas. The findings of this article show that the positive impacts of self-driving cars are mainly in the areas of ease of travel and self-driving car fleets. The negative impacts are mainly reflected in three different aspects: safety hazards, environmental pollution and energy consumption. Of course, self-driving cars have different impacts in various fields, and these impacts need to be explored by more researchers.