In view of the strong nonlinear and strong coupling characteristics of the heat flow equation, a linear optimization method based on multivariate function taylor expansion is proposed. This method transforms the complex nonlinear optimization problem into multiple linear optimization problems that are easy to solve. An iterative method is used to gradually approximate the optimal solution between optimization problems. Taking the minimum total network loss of the electro thermal interconnect system as the optimization goal, the parameter optimization configuration of multiple cogeneration units can be realized at the same time, the network loss is reduced, the system operation cost is reduced, and coupling complementarity and coordinated operation is achieved between different energy sources, which can improve system scheduling, economy and security. The test analysis of the actual system verifies the validity and rationality of the proposed method.