Two-dimensional (2D) niobium silicon telluride (Nb ₂SiTe ₄) was recently proposed as a promising candidate in infrared detector, photoelectric conversion, polarized optical sensor and ferroelastic switching application due to its narrow bandgap, long-term air stability, high carrier mobility, etc. However, the in-plane strains and interfacial defects induced by the lattice misfits between functional layers are harmful to 2D heterojunction nanodevice performance, making the crystal-lattice regulation and strain engineering necessary to achieve lattice matching and strain-controllable interface. Here, using first-principles calculations and elemental substitutions, i.e., replacing cations (anions) with elements in the same group of periodic table, we identify three new and stable single-layer A ₂ BX ₄analogues (Nb ₂SiSe ₄, Nb ₂SnTe ₄and Ta ₂GeTe ₄) as appealing candidates in manipulating the lattice parameters of Nb ₂SiTe ₄. The controllable lattice parameters are 6.04 Å ≤ a≤ 6.81 Å and 7.74 Å ≤ b≤ 8.15 Å. Among them, Ta ₂GeTe ₄exhibits similar lattice parameters to Nb ₂SiTe ₄but smaller bandgap, yielding better response in far-infrared region. Strain engineering shows that the external biaxial tensile stress narrows the bandgaps of A ₂ BX ₄due to the downshifting in energy of conduction band minimum (CBM). External biaxial compressive stress induces valance band maximum (VBM) orbital inversion for Nb ₂SiTe ₄, Nb ₂GeTe ₄and Ta ₂GeTe ₄, which pushes up VBM and discontinues the trend of corresponding bandgap increase. In this case, the bandgap change depends on the competition between energy upshifts of both CBM and VBM. In the Nb ₂SiSe ₄and Nb ₂SnTe ₄cases, the d-p antibonding coupling in valance band is so strong that no valance band inversion appears while the bandgap increases by ~0.3 eV under −5% compressive strain. Regarding Nb ₂SiTe ₄, Nb ₂GeTe ₄and Ta ₂GeTe ₄, their bandgaps can hardly change under −5% compressive strain, indicating that the energy upshift in VBM equals that in CBM. Such a valance band inversion is attributed to Te outmost porbital overlapping, which introduces more dispersive VBM and smaller effective mass of hole. Our findings suggest that Nb ₂SiTe ₄can be alloyed with Nb ₂SiSe ₄, Nb ₂SnTe ₄and Ta ₂GeTe ₄to achieve controllable device lattice matching while maintaining its superior properties at the same time. The use of external biaxial compressive stress can promote the hole diffusion and improve the device performance.