The paper presents a novel approach to constructing all-antiferromagnetic tunnel junctions (MTJs) down to the atomic limit using a twisting strategy. By twisting two bilayers of CrSbR, a 2D antiferromagnetic material, a significant nonvolatile tunnelling magnetoresistance (TMR) ratio of over 700% is achieved at zero field (ZF). This is attributed to the cumulative coherent tunnelling across individual CrSbR monolayers. The dependence of the TMR on the twist angle is calculated and found to be in good agreement with experimental results, showing that the TMR ratio increases with decreasing twist angle. Additionally, the temperature dependence of the TMR is weaker in the twisted junctions compared to untwisted junctions, making them more suitable for applications. The study demonstrates that it is possible to achieve nonvolatile magnetic information storage at the atomically thin limit using all-antiferromagnetic MTJs. The physical mechanisms behind the giant TMR effect are also explored, revealing that the spin-dependent potential barrier of CrSBr is twist-angle-dependent due to the rotations of the in-plane wavevector and spin. The findings establish a compelling strategy for achieving all-antiferromagnetic MTJs in the atomic limit, with potential applications in high-density and ultrafast information devices.The paper presents a novel approach to constructing all-antiferromagnetic tunnel junctions (MTJs) down to the atomic limit using a twisting strategy. By twisting two bilayers of CrSbR, a 2D antiferromagnetic material, a significant nonvolatile tunnelling magnetoresistance (TMR) ratio of over 700% is achieved at zero field (ZF). This is attributed to the cumulative coherent tunnelling across individual CrSbR monolayers. The dependence of the TMR on the twist angle is calculated and found to be in good agreement with experimental results, showing that the TMR ratio increases with decreasing twist angle. Additionally, the temperature dependence of the TMR is weaker in the twisted junctions compared to untwisted junctions, making them more suitable for applications. The study demonstrates that it is possible to achieve nonvolatile magnetic information storage at the atomically thin limit using all-antiferromagnetic MTJs. The physical mechanisms behind the giant TMR effect are also explored, revealing that the spin-dependent potential barrier of CrSBr is twist-angle-dependent due to the rotations of the in-plane wavevector and spin. The findings establish a compelling strategy for achieving all-antiferromagnetic MTJs in the atomic limit, with potential applications in high-density and ultrafast information devices.