The output of distributed renewable energy fluctuates greatly and the electrical and thermal loads vary randomly in the combined heat and electricity system. A steady state energy flow model with uncertainties for the combined heat and electricity system is established. A low deviation point series through Sobol point series is constructed. Based on the quasimonte carlo simulation method, random variables are sampled, and the correlation between random variables is considered to solve the probabilistic energy flow of the combined heat and electricity system. The case shows that the proposed method has good convergence stability,which lays a foundation for the subsequent research on the safety analysis of the combined heat and electricity system.