KBe2BO3F2 (KBBF) is still the only practically usable crystal that can generate deep‐ultraviolet (DUV) coherent light by direct second harmonic generation (SHG). However, applications are hindered by layering, leading to difficulty in the growth of thick crystals and compromised mechanical integrity. Despite efforts, it is still a great challenge to discover new nonlinear optical (NLO) materials that overcome the layering while keeping the DUV SHG available. Now, two new DUV NLO beryllium borates have been successfully designed and synthesized, NH4Be2BO3F2 (ABBF) and γ‐Be2BO3F (γ‐BBF), which not only overcome the layering but also can be used as next‐generation DUV NLO materials with the shortest type I phase‐matching second‐harmonic wavelength down to 173.9 nm and 146 nm, respectively. Significantly, γ‐BBF is superior to KBBF in all metrics and would be the most outstanding DUV NLO crystal. Two excellent deep‐UV nonlinear optical crystals, NH4Be2BO3F2 (ABBF) and γ‐Be2BO3F (γ‐BBF), have been synthesized based on first‐principles design. They not only effectively overcome the layering habit of KBBF, but also can generate deep‐UV (DUV) coherent light with wavelengths down to 173.9 nm and 146 nm, thus indicating that they are superior to KBBF.