In order to realise the function of focusing by single flat lens, this paper proposed a electromagnetic focus meta-surface working on 10.6 μm wavelength which has one dimensional subwavelength grating structure. According to the resonance between dielectric nanostrcture and light, based on the coupled rectangular dielectirc resonators model, unit structure was designed. Using FDTD solution software for simulation, the function of phase modulation can be proved and 10 phase gradient structures can be selected. The meta-surface was designed by the free  combination of the 10 structures and tested by experiment. Result shows that, at 10.6 μm wavelength, when TM mode light incident the meta-surface, transmitted light will be focused, focal length is 49mm, the minimum value of the spot width is 0.7 mm, and working efficiency can be reached to 60 %.