By 2018, China will carry out the national carbon trading policy. In the carbon trading market, the power suppliers are facing with the risk of uncertainty in the carbon trading price. Considering the risks of carbon trading, the low carbon dispatch problem of power suppliers is worth studying. Drawing on the theory of risk management in financial field, this paper uses conditional value at risk (CVaR) as a risk measurement index, and proposes a low carbon dispatch optimization model for power suppliers considering the risks of carbon trading. The model is used to calculate the carbon trading portfolio optimization of power suppliers. At the same time, the impacts of power suppliers risk preference confidence, changes in carbon trading prices and carbon emission limits on the carbon trading risks of power suppliers are analyzed. The effectiveness of the proposed model is verified by examples. The power suppliers can optimize the power generation, balance profits and risks by using the model, and the model has a certain reference value and guiding role for the power suppliers business decisions.