The lightweight refractory high entropy alloys (RHEAs) can be considered the best alternative to Ni-based superalloys, which has significantly increased the attention of researchers. In this study, the newly designed lightweight (ρ ∼ 6.2 g/cm³) Al_0.5Ti₂Nb₁Zr₁W_X (X: 0, 0.3, 0.5, 0.7) RHEAs were prepared. Our results evidence that the microstructure of Al_0.5Ti₂Nb₁Zr₁W_0.5 RHEA has a BCC structure merged with B2 nano-precipitates, which leads to significant improvement in the specific yield strength (SYS) compared with other RHEAs. Besides, the compressive SYS (σ_0.2/ρ) of Al_0.5Ti₂Nb₁Zr₁W_0.5 RHEA at 298 K, 973 K, and 1078 K are as high as 187 MPa g⁻¹ cm³, 128 MPa g⁻¹ cm³, and 95 MPa g⁻¹ cm³, respectively. Interestingly, Al_0.5Ti₂Nb₁Zr₁W_0.5 RHEA exhibited excellent ductility (greater than68 %) under compression at temperatures from 298 K to 1273 K. The distinct deformation mechanisms at 973 K and 1273 K are discussed as well. Initially, the strain hardening capability is provided by dislocation-dominated deformation. Conversely, with an increase in the strain, the micro-crack development and dynamic recovery (DRX) trigger the conversion from strain-hardening to persistent flow softening when the temperature is raised from 973 K to 1273 K. The persistent flow softening at 1273 K is primarily due to diffusion-controlled dislocation annihilation and continuous (DRX).