With the continuous development of additive manufacturing technology, it has emerged as the core driving force for innovation in the manufacturing sector. Currently, the commonly employed metallic materials for additive manufacturing include stainless steels, nickel-based superalloys, aluminium alloys, and titanium alloys. However, these materials do not fully satisfy the complex and variable application requirements. Hence, the development of new alloys suitable for additive manufacturing is particularly important. This study focuses on the development of a new Fe-Cr-Ni alloy via laser powder bed fusion based on 316L stainless steel and IN718 nickel-based superalloy powders. The results indicate that through laser powder bed fusion, good in situ alloying is achieved, and the alloy exhibits excellent printability. Additionally, this alloy demonstrates good room-temperature tensile properties, with a tensile strength and yield strength of (875±14) MPa and (675±14) MPa, respectively, maintaining an elongation to fracture of 22.9%±3.8%.