To improve the internal quantum efficiency (IQE) and light output power of InGaN light-emitting diodes (LEDs), we proposed an In-composition gradient increase and decrease InGaN quantum barrier structure. Through analysis of its P-I graph, carrier concentration, and energy band diagram, the results showed that when the current was 100 mA, the In-composition gradient decrease quantum barrier (QB) structure could effectively suppress electron leakage while improving hole injection efficiency, resulting in an increase in carrier concentration in the active region and an improvement in the effective recombination rate in the quantum well (QW). As a result, the IQE and output power of the LED were effectively improved.