Abstract: Prefabricated steel-beam structures are becoming a trend in school buildings, and the sound environment of classrooms has also received more and more attention. Reverberation time is one of the important indicators in the design of classroom sound environment. In this paper, with the aim of obtaining more accurate and applicable calculation methods, the calculation of reverberation time in classrooms under discrete and non-uniform sound absorption conditions is studied. Two typical steel-beam structure classroom geometries are selected, and three different types of absorption arrangements are adopted on the ceiling beam. The reverberation times from 125 Hz to 4 kHz octave bands are calculated using five different models and then compared with the corresponding measured results. The results show that the reverberation time spectrum obtained by five different calculation methods have similar trends, but there are significant differences in numerical values. The Sabine formula and Arau method can obtain more consistent results with actual measurements, while the Arau method can provide more accurate estimates of reverberation time under various sound absorption conditions.