Online-hailing taxi (hereinafter referred to as "online car-hailing") is an important part of urban passenger transport. Its service quality directly affects the travel experience of the people and the development of the industry. Therefore, it is urgent to build a scientific and systematic evaluation index system for the quality of online car-hailing services, which provides a reference for regulating and improving the service quality of online car-hailing industry in China. The semantic analysis on the online comments of the Didi Travel APP is conducted. Combining three methods for extracting keywords, a keyword dictionary and the operation results of the LDA topic model are constructed. By consulting the relevant literature and industry norms and drawing on the SERVQUAL (Service Quality) model, a service quality evaluation index system for online car-hailing services is constructed, which includes 6 dimensions and 29 evaluation indicators. The evaluation index system for the quality of online car-hailing services constructed using online reviews as the basic data can well meet the three evaluation principles of scientificity, practicality and independence.