Friction stir welding (FSW) of high-strength materials and thicker plates has a number of challenges that are preventing widespread industry application such as (i) premature tool failure, (ii) selection of tool material and design, and (iii) weld productivity. A finite element (FE) based analysis for Laser-FSW hybrid welding technology is carried out in ABAQUS, commercially accessible FE software, to solve these typical difficulties. The thermal analysis of Laser-FSW hybrid technique is done using two moving heat sources for the case of 3.2 mm thick S45C steel plate. A negative moving heat source is placed as a replacement of the backing plate material in the high contact pressure region under the FSW tool. It was shown that the laser heat source needs to be 10 mm ahead of the FSW tool for achieving the duplex phase (Ferrite + Bainite/Martensite) microstructure.