In order to study the nature of the speckle field,an experimental sch eme to generate speckle vortices which based on the Archimedes′ spiral nano-slit is proposed .First,we theoretically analyze the expression of the light field produced by the plane light perpendicu lar to the diffraction screen where the Archimedes spiral is located.Then,the light field distributio n image is obtained by numerical simulation.In the experiment,the hologram of the Archimedes′ spiral nano-slit is displayed on the screen of a phase-only reflective liquid crystal spatial light modulator (LC-SLM).The collimated plane beam is illuminated on the screen of the LC-SLM,and the diffracted light field generated by the Archimedes′ spiral nano-slit is captured by the CCD camera.In the experiment ,the diffracted light field passing through the Archimedes′ spiral nano-slit is interfered with th e oblique incident plane light,and the interference fringe appears bifurcation.The bifurcation of the i nterferograms indicates the presence of the speckle vortices with a unit topological charge in the speck le field.The experimental results are consistent with the numerical results.Numerical simula tions and experimental results show that the unit topological charge optical vortex can be generated by using Archimedes′ spiral nano-slit.The Archimedes′ spiral nano-slit structure ma y provide potential applications in optical capture,optical imaging and so on.