Chromatism　generally　exists　in　most　metasurfaces.　Because　of　this,　the　deflected　angle　of　metasurface　reflectors　usually　varies　with　frequency.　This　inevitably　hinders　wide　applications　of　metasurfaces　to　broadband　signal　scenarios.　Therefore,　it　is　of　great　significance　to　overcome　chromatism　of　metasurfaces.　With　this　aim,　we　firstly　analyze　necessary　conditions　for　achromatic　metasurface　deflectors　(AMD)　and　deduce　the　ideal　dispersions　of　meta-atoms.　Then,　we　establish　a　Self-Organizing　Map　(SOM)　Neural　Network　as　a　prepositive　model　to　obtain　a　diversified　searching　map,　which　is　then　applied　to　Greedy　Algorithm　to　search　meta-atoms　with　the　required　dispersions.　Using　these　meta-atoms,　an　AMD　was　designed　and　simulated,　with　a　thickness　about　1/15　the　central　wavelength.　A　prototype　was　fabricated　and　measured.　Both　the　simulation　and　measurement　show　that　the　proposed　AMD　can　achieve　an　almost　constant　deflected　angle　of　22°　under　normal　incidence　within　9.5–10.5GHz.　This　method　may　find　wide　applications　in　designing　functional　metasurfaces　for　satellite　communications,　mobile　wireless　communications　and　others.　©　2020　Optical　Society　of　America　under　the　terms　of　the　OSA　Open　Access　Publishing　Agreement