The higher firing temperature reflects the higher efficiency of the gas turbine. However, using higher temperatures is limited as it may cause a rupture, bending, or failure of the turbine blades. Hence, the development of an effective internal cooling system of the gas turbine blade is essential. At the same time, it is necessary to ensure the lowest possible penalty on the thermodynamics performance cycle. Researchers are working over the years to find out the efficient cooling channel design with high transfer while the lowest pressure drop. They ran several cases both numerically and experimentally. This paper reviews the published research in the various methods of gas turbine internal cooling, such as using rib turbulators, dimples, jet impingement, pin fins, and guide vane, of the gas turbine blade.