AlGaN/GaN-HEMT with Single to Multi-step gate field plate is proposed in this work. The proposed device enhanced Drain current, breakdown voltage and shift in threshold voltage. The performance of proposed device is analyzed and compared with experimental step device with and without Field Plate (FP). Reduction of current collapse effects is proved with Multi Gate Step field Plate in AlGaN/GaN HEMTs. The performance of the devices is analyzed using Technological Computer Aided Design (TCAD). In the simulation, polarization, mobility, recombination and impact ionization models are used. The electric field, potential and current density of the GaN-HEMT are analyzed. From the TCAD simulation, GaN-HEMT with increment in-step FP yields higher breakdown voltage than that of other FP techniques. Hence, the proposed GaN-HEMT is an outstanding candidate for future high power application.