Currently, bio-medical and automotive industries use thermoelectric module to reproduce electrical energy from wasted heat energy. Thermoelectric generator (TEG) modeling and simulation will be hashed out further in this paper to achieve improvement. Finite element method (FEM) model, circuit equivalent model and mathematical/computer model are various methods employed to model the thermo-electric generator. Analysis of FEM modeling requires a high tier of knowledge of an engineer in material engineering. The circuit equivalent model uses the electrical circuit analogy to describe heat transfer and electrical behavior in TEG. In this work, the mathematical derivation of circuit equivalent model is used in computer models by using Simulink (Matlab). The result of the computer model can be an alternative model for electrical or electronics engineers to improve TEG performance in the future.