With the development of urbanization, the traffic problem has become a big problem to big cities. Rail transit is preferenced by big cities because it has the advantages of rapid, punctual, large capacity, low carbon and environmental protection. It is gradually becoming one of the means to ease the ground traffic pressure and guide the rational development of the city. Lanzhou is currently starting to build rail transportation, so it is necessary to reveal the influence which the rail transit construction will bring to the future development of Lanzhou, and take some measures ahead of time to maximize the benefits which the rail transit will bring. Firstly, this paper unscrambles the evolving relation between Lanzhou development and transportation starting from the historical perspective. Secondly, based on gravity field model and accessibility model this paper analyses the change which will happen to city before and after rail transit construction, then this paper analyses the effect which rail transit will bring to Lanzhou pro and con. The positive effects mainly include guiding the city space form, adjusting the city layout, changing the land use surrounding the site and improving the urban environment.The negative effects mainly include the direct impact noise of vibration, electromagnetic interference, increasing pollutants, and the possible impact of the land over exploited surrounding the site and excessive agglomeration in the core area of Chengguan. Finally, from two aspects of positive and negative, this paper puts forward some corresponding measures to maximize the benefits which the rail transit brings.The positive impact of response measures mainly are leading the regional balanced development, restructuring city comprehensive transportation system, strengthening the control and guide of the land surrounding the site. The negative impact of response measures mainly are reducing the impact by technology, strengthening the management of sanitation facilities, strengthening monitoring and management of the control regulation and easing the function of chengguan’s core area.