This review comprehensively summarizes the recent researches of CrCoNi-based multi-component alloys which have attracted broad interest of researchers at home and abroad. The development history and research progress of CrCoNi-based alloys are briefly introduced. The deformation mechanism of the alloy is analyzed in detail, including the formation of the deformation twins and the effects on mechanical properties. Secondly, the effects of various processing techniques including cold rolling, hot rolling and additive manufacturing on the microstructures and mechanical properties of the CrCoNi-based alloy are presented. At present, the most widely used method of preparing CrCoNi alloy is “casting-cold rolling-heat treatment”. However, some researchers have discovered that the mechanical properties of the additive manufactured CrCoNi-based alloys without any post heat treatment are comparable to that of the alloys prepared by the traditional cold rolling and heat treatment, indicating that CrCoNi alloy is very suitable for additive manufacturing. Then the influences of various alloying elements on the microstructures, phase stability and mechanical properties of the CrCoNi-based multi-component alloy are also discussed. Among them, the addition of Al and Ti has the strongest strengthening effect on the CrCoNi alloy, which causes the precipitation of γ′ phase on the FCC matrix, improving the mechanical properties of the alloy. Finally, future research directions and potential applications of CrCoNi-based alloys are proposed.