The invention discloses a culture method for multicolor magnolia flowers. The method mainly comprises steps: parent plant cultivation, tissue grafting, culturing management after grafting, and vegetative propagation character stabilization. The multicolor magnolia flowers cultured by the method can have multiple colors and multiple flower types, and on a same magnolia flower tree, flowers can be white, purple, lavender, yellow, and rosy. Growth of plants is robust, the number of flowers is multiple, and florescence is long. The method shortens cultivation time, reduces variety breeding cost, and improves ornamental value and economical value of the magnolia flowers.