The solar brightness model is widely applied in modeling and optimization of concentrated solar energy system. In this paper, the influence of various solar brightness models on the solar dish system are evaluated. The spline interpolation to the test data of solar brightness distribution is applied as the standard model, and the performance simulation and optimization code for solar dish system with the standard model are built and validated by Soltrace. The optical efficiency of different solar brightness models are calculated. The prediction and optimization error of 11 solar brightness models are estimated under different optical error, rim angle of reflector, concentration ratio, and circumsolar ratio. Although prediction results are rather good when optical error is more than 5 mrad, the prediction and optimization results exists much error between the present solar brightness model and the standard model especially when the optical error is less than 5 mrad, in which the maximum error of 40% exists when considering the influence of CSR for the performance modelling and maximum relative error of 3.5% for optimization. As the optical error of the solar dish system has been greatly reduced recently, it is recommended that the precise model for solar brightness distribution should be applied for obtaining better performance prediction and optimization. (C) 2019 Elsevier Ltd. All rights reserved.