This experiment was use of photoluminescence (Photoluminescence, PL), electroluminescence (Electroluminescence, EL) and Advanced Physical Models of Semiconductor Devices (APSYS) simulation software such as samples for optical and electrical characteristics analysis. We change the input power for Photoluminescence and electroluminescence measurements to explore the impact on low temperature and room temperature for InGaN/GaN multiple quantum well LED internal quantum efficiency of the physical characteristics. In the electroluminescence measurement, it was found that under high-current injected at low temperature. The hole concentration and mobility was trend down. The hole distribution was not uniform in the quantum well and because the hole mobility decreased, lead to more effective hole can not be injected into the quantum wells and the accumulated in close proximity to the p-GaN quantum wells. The quantum wells is also due to the lack of hole resulting in more electron overflow to p-GaN. Result the internal quantum efficiency droop on high current injection. The experimental measurement of the Sample for the three different quantum well thickness for the blue LED, respectively, 1.5nm, 2.0nm, 2.5nm, to analyze the different light-emitting properties, the establishment of the equivalent LED model, which can be divided into the leakage current, Radiation composite current, non-radioactive compound current, and high injection current caused by the overflow. The high-injection current was lead to Auger effects that the efficiency droop with the current increase. The Photoluminescence (PL) and APSYS simulation result also same as Electroluminescence.