The invention discloses a nappa leather coating composition and a coating technology thereof. The nappa leather coating composition comprises scraping-touchup slurry, base sealing slurry, base slurry, isolation slurry, surface slurry and bright slurry; and the coating technology comprises the steps of crust milling, toggling, mending of blemishes, surface grinding, dust removal, base sealing, first ironing, base slurry brushing, pressing of coarse needle lines, base slurry spraying, spraying of an isolation layer, pressing of nappa lines, second milling, first vibration staking, second ironing, surface slurry spraying, spraying of a bright layer and third ironing. The nappa leather coating composition disclosed by the invention is used for processing common leather into high-grade nappa leather so that the nappa leather has natural lines and comfortable handfeel, and the leather grade is promoted.