The invention discloses a planting method of thorn-free pepper. Annual branches of red pepper are cut, scions are obtained and grafted on seedlings of the red pepper, thorn-proof essence is sprayed in grafted positions during grafting, and the thorn-proof essence is a hoar-frost liquid on thorn-free melon and fruit surfaces. Branches and leaves of obtained pepper trees are thorn-free, and the pepper is free of pollution and residues, has a sufficient spicy flavor, full grains, thick pulp and small grains, is high in yield and has very high economic value.