DC–DC boost converters are unable to provide high step-up voltage gains due to the effect of power switches, rectifier diodes, and the equivalent series resistance of inductors and capacitors. A high step-up DC-DC converter based on the modified SEPIC converter is presented in this paper. Step up non-isolated converters generally suffer from problems such as high voltage stress and low efficiency. In this study, non-isolated boost converter structures, SEPIC, SEPIC modified circuit, and a proposed converter is studied. Then compare the performance of these typologies is located and presented as a chart. The operation analysis, design procedure for proposed converter is obtaied from 15V input voltage and 150V output voltage and with 100 watts output power. Using the proposed converter, the input inrush current and the invading voltage of the output have decreased. The time response analysis states that the proposed converter acts faster with deployment time than other converters.