A plasmonic lens constructed with elliptical pinholes ranging from micron to nanoscales distributed in variant periods along the radial direction was presented. Our computational numerical calculation results demonstrated that an ultra-enhanced lasing effect exists while linear polarized plane wave illuminates and passes through the pinholes. The lasing effect can extend the longitudinal focal region and reach as long as 12 A mu m along the propagation direction. Benefiting from the lasing effect, depth of focus with extraordinarily elongated length (three orders of magnitude in comparison to that of the conventional microlenses) is generated accordingly. Undoubtedly, it may be helpful for practical applications such as data storage, photolithography, and bioimaging.