The principle and design method of optical super-oscillation are introduced. A superoscillatory optical field with a local superresolution is experimentally obtained by pure amplitude-modulated spatial light modulator (SLM) and digital micro-mirror device (DMD). The experimental results show that the characteristic size of the superoscillatory field in the generated superresolution optical field is sixty percent of diffraction limit. The analysis of the spatial spectra used to validate the experimental results shows that the superoscillatory optical field does not generate spatial high frequency components beyond the diffraction limit.