An absolute calibration method based on rovibrational Raman scattering has been introduced in this paper. Recently, a multi-channel Littrow spectrometer has been developed and integrated into the TVTS (Television Thomson Scattering) system on EAST. The spectrometer adopts a Littrow configuration, featuring a high entrance slit (70 mm) and high spectral dispersion (∼3.8 nm mm−1). Considering the structural characteristics of the spectrometer and the requirements for absolute calibration accuracy of Thomson scattering diagnostic, we have developed Raman calibration technology based on rovibrational transitions. From the experimental results, it is evident that rovibrational Raman scattering can demonstrate excellent linearity within a certain range and provide highly accurate calibration results for TVTS. Based on this, we have obtained reliable profiles of TVTS temperature and density on EAST. The estimated measurement errors are approximately 15% for electron temperature and 10% for electron density.