The development of high-performance Co-free multiprincipal component alloys (MPCAs) is of great significance in recent years. In the present work, eight arc-melted Co-free AlxCrFeMn2-xNi alloys were prepared and then vacuum annealed at 800 or 1000 °C for 5–10 days. Their phase constituents, microstructures and mechanical properties were investigated. The second-order L21-Ni2MnAl phase with low Cr and Fe content was confirmed and had similar contribution to the alloy hardness as B2 phase. When x ≥ 1, the as-cast AlxCrFeMn2-xNi alloys are composed of BCC + B2 phase and have an elastic modulus of ∼228 GPa. Their mechanical properties slightly change after annealing, although the phase grains are coarsened after 1000 °C annealing and small amount of FCC phase precipitated after 800 °C annealing. When x = 0.1–0.75, the BCC phase transforms into the σ phase after 800 °C annealing, which leads to greatly increased hardness and reduced ductility. The decomposition temperature of the σ phase decreased with Al content, from 1036.9 °C to 912.0 °C. Compared to the AlxCo2-xCrFeNi alloys, the similar phase constituent and similar hardness can be obtained by replacing Co with Mn. Therefore, Co-free Al–Cr–Fe–Mn–Ni MPCAs have great application prospects.