The Senegalese was sent off in the 67th minute at Upton Park for a challenge on Dwight Gayle, with West Ham leading 2-1 in a game that ended 2-2.
Kouyate, 26, will now be available for Saturday's visit of Arsenal.
An FA statement read: "An independent regulatory commission has upheld a wrongful dismissal claim."
West Ham midfielder Cheikhou Kouyate's red card against Crystal Palace on Saturday has been rescinded by the Football Association.