The impact of utilizing Nanofluids with different metal oxide nanoparticles on heat transfer enhancement and fluid flow for concentration photovoltaic thermal the CPVT collector with Fresnel lens is demonstrated using CFD simulation. With the rising temperature, the electrical efficiency and output power of Multi-Junction Solar Cells drop. Four different types of nanofluids and water are utilized as cooling fluids to disperse heat from Multi-Junction Solar Cells by moving the fluid within the mini-channel beneath the PV Solar Cells. In the current analysis, the Reynolds numbers range from 2000 to 18000. For all forms of cooling fluids, the average Nusselt numbers are augmented by rising Reynolds numbers. The CFD results demonstrated that the Nusselt number of all nanofluid cooling fluids is greater than that of water. When compared to water in a CPVT collector, water-SiO2 nanofluid provides the maximum heat transfer improvement of 12.5%. The silicon dioxide nanoparticles have high thermal conductivity, with the water-SiO2 nanofluid exhibiting the greatest heat transfer increase, followed by water-Al2O3, water-ZnO, water-CuO, and water. The average top surface temperature of the mini-channel for the CPVT collector is reduced by 7% when water-SiO2 nanofluid is used as a cooling fluid and by 3.4% when water is used. The usage of water-SiO2 nanofluid has a significant impact on the heat dissipation with high heat transfer enhancement from Multi-Junction Solar Cells in CPVT collector, leading to an increase in electrical efficiency.