In the present paper the two-stage model of detonative combustion of hydrogen is presented. The following improvements are described: accurate description of the heat release stage of combustion; the clear physics-based procedure for calculation of the parameters of the proposed model; sample calculations of the detonation wave in hydrogen/air mixtures in wide range of conditions, showing that the proposed model performs well in a wide range of conditions (pressures, temperatures, mixture compositions). The results of the 2D simulations of the detonation cell are presented for the hydrogen/oxygen/argon mixture as example to show the performance and accuracy of the model, presented in this paper.