Using density functional theory (DFT), the effect of the axial strain on the ionic structure and electronic properties of a (6,0) zigzag single-walled silicon carbide nanotube (SiCNT) is investigated at the M05-2X/6-31+G(d) level of theory. The structural parameters, binding energy, energy gap, dipole moment, chemical potential, chemical hardness and softness, electrophilicity index, NBO charge, radial buckling, and the maximum amount of the electronic charge for pristine and strained SiCNT are calculated. The calculated binding energy for pristine SiCNT is estimated to be smaller than that of the stretched nanotube. According to our calculation, the tube diameter and the iconicity of Si-C bonds decrease and the energy gap increases under the axial strain. Thus, the electronic properties of SiCNTs can be tuned by the axial strain in a wide energy range. It is predicted that pristine SiCNT is more suitable for photoconductivity applications than the stretched one.