[Purpose/significance] In order to effectively solve the traffic congestion problem in megacities, it is important to explore the effective application of digital twin technology in urban transportation planning. [Method/process] This article begins by providing an overview of the main content of digital twin technology. Secondly, it analyzes the spatial distribution of urban transportation facilities using the POI data from Amap, with Chengdu City as an example. Methods such as kernel density estimation are employed to examine the spatial distribution of urban transportation facilities in 2016 and 2022, aiming to grasp the current status and existing problems in the planning layout of transportation facilities in megacities. Finally, it explores the path for megacities to achieve digital twin smart transportation planning. [Result/conclusion] Chengdu has focused on alleviating the traffic congestion problem in the central urban area over the past four years. However, due to high land utilization in the central urban area, the existing roads have long been unable to meet the increasing daily traffic demands. Parking difficulties and the long time spent finding parking spaces have become the second challenge for citizens driving in the city. Although Chengdu has shown a trend of traffic overflowing from the central urban area, the pendulum traffic in the twin cities will still increase the pressure on public transportation during peak hours. Therefore, it is necessary to realize the digital twin intelligent transportation planning of megacities by laying out sensing equipment, using digital twin visualization technology, and improving P+R planning.