In order to optimize the layout of river network, it is necessary to clarify the impact of urbanization on the river network. Based on remote sensing images and river network data of three time periods (2000, 2010 and 2020), the spatial and temporal evolution characteristics of the river network in Xi’an City was analyzed from river network quantitative and structural perspectives to reveal the quantitative relationship between urbanization level and river network characteristics. The results show that the area of construction land has been increasing over the past 20 years, accounting for 13.25% of the total area of the Xi’an City in 2020, and the process of urbanization has changed from the accelerated stage of development to the mature stage. The quantitative parameters of the river network in Xi’an City showed a continuous decreasing trend, with the density of the river network and water surface ratio decreasing by 26.47% and 20.69%, respectively. The structural characteristics of the network including river development coefficient and river network complexity showed an increasing and then decreasing trend, but overall attenuation trend, with an attenuation rate of 19.87% and 17.01%, respectively. In regions with different rates of urbanization, the spatial distribution of the river network pattern varied significantly, but under the joint action of natural factors and human activities, the stability degree of the overall river network structure in Xi’an city was improving towards 1, and the development of the river network was relatively stable. Changes in river network patterns were strongly influenced by urbanization, among which the influence of urbanization on river network complexity and water surface ratio were greater than that on river network density and river development coefficient.