One of the most useful DC-DC converters is called the boost converter, and they are used to increasing and stabilize the output voltage in renewable energies such as thermoelectric Generator systems. For converter of TEG systems, The structures have been provided, which can be mentioned as single switch cascaded boost converter. The choppers are non-linear in nature, so fixed parameter controllers cannot display a suitable dynamic behavior for step and parametric changes, so designing a suitable controller in regard to uncertainties such as temperature changes has become an important challenge. In this research, moreover the experimental modeling of the TEG module, a nonlinear controller based on Offered Feedback Linearization (OFBL) method is proposed to control the output voltage of the cascaded boost chopper, and its coefficients are also optimized by GA. In order to check the transient response of the aforementioned converter, the ITSE function is considered. For evaluating the proposed controller, five scenarios of constant input, step-up changes, step-down changes and combined changes in input voltage and Apply TEGS as input have been analyzed. Also, at the end of the simulation, the output load changes are considered. The mentioned simulations were done in Simulink MATLAB. The results of the simulations state that the proposed controller, due to its simple structure, has succeeded in tracking the reference voltage and has demonstrated an acceptable performance for stabilizing the output voltage, especially in TEG systems.