Shared transportation has been one of the essential components of shared cities. This paper aims to understand the universal laws governing the bike-sharing system using the massive ridership data from Mobike, one of the largest bike-sharing schemes in the world. The analysis is conducted at the intracity and intercity levels while considering the relationship between Mobike shared bikes and built-environment. The first component of this paper is to calculate the Mobike riding index (MRI), a way to measure the bike-friendliness of cities. After calculating the MRI, we further studied the nation-wide distribution of MRI in different analytical levels and investigated its patterns. Results show that at the street level, the weekday MRI distribution is analogous to that of the weekend’s; at the township level, highly scored townships are those close to the city center; at the city level, the MRI distributes unevenly, with high MRI cities staying along the southern coastline or the middle inland area, such as Shenzhen, Chengdu, and Wuhan.