A super-resolution focusing and easy integrated sub-wavelength metal single-slits containing mental strip structure is proposed based on sub-wavelength metal slit focusing structure. The focusing properties of the structure are simulated and analyzed by using electromagnetic field simulation software finite difference time domain (FDTD). Through the analysis of structural parameters of focusing structure influence on the focusing effect, a high focusing intensity of I=4.5 and a small spot size with full width half maximum (FWHM) of 300 nm (lass than λ /2, λ =632.8 nm) is achieved. Meanwhile, the structure′s deviation and positioning accuracy of ±10 nm have little effect on the focusing property. Such a focusing structure with the predicted focusing efficiency has potential practical applications in nanophotonics and integrated photonics due to the small lateral dimension size of only about 2.0 μm.