Abstract: A simplified Solomon pyrolysis model for simulating HCN release in NO formation during coal combustion is proposed. A full two-fluid model together with the k-ε-k_p two-phase turbulence model, the EBU-Arrhenius combustion model, the six-flux radiation model, and two different HCN release models are used to simulate gas-particle flows, coal combustion, HCN release and NO formation in a swirl burner. Comparison of predictions with experimental results taken from references indicates that the HCN release model based on the simplified Solomon pyrolysis model is better than the original HCN release model based on the two-equation pyrolysis model.