The invention discloses a method for cultivating camellia bonsai by a two-step grafting method of Camellia oleifera roots, which includes digging Camellia oleifera and selecting roots, the first step of grafting, putting in pots, promoting germination and promoting shoots, the second step of grafting, management and In the shaping and pruning process, suitable roots of camellia oleifera are selected as grafting rootstocks, and camellia plant branches are collected as grafting scions, and the first step of grafting is carried out by cutting grafting. When the scions grafted in the first step survive for more than 6 months, the camellias are collected The plant branch is used as the grafted scion, and the new shoots drawn from the scion grafted alive in the first step are used as the rootstock for grafting, and the split grafting method is used to carry out the second step of grafting. After management, the grafted camellias are trimmed according to the ideal shape of the bonsai. The invention adopts the root grafting of camellia oleifera to realize fast replanting of low-yield camellia oleifera forest, promotes the existing large-area low-yield camellia oleifera forest transformation project in China, reduces waste of resources, and has strong ornamental value.