Abstract The performance for GaN-based light-emitting diodes (LEDs) with specially designed composite electron blocking layers (CEBLs) that are inserted between the InGaN/GaN multiple quantum wells (MQWs) and the top p-GaN layer was studied intensively. The CEBLs are consisted of an AlGaN layer and a p-InAlGaN/GaN superlattice (SL). The simulation results indicated that the light output power and internal quantum efficiency for the GaN-based LED with CEBLs could be enhanced by 35.6% and 36% at an injection current of 350 mA, respectively, as compared to the previous GaN-based LED only with p-InAlGaN/GaN SL EBL. The improved uniformity of carrier distribution, the enhanced hole concentration and injection efficiency, as well as the increase in effective potential height for electrons and the decrease in the strain-induced polarization electric field are identified to be responsible for this significant improvement.