The utility model relates to a high temperature chromosome multiplication device for a tree, which is a heating device and comprises a box body, a heating part for heating the box body and a supporting part which the box body is fixed on a tree by. The high temperature chromosome multiplication device for a tree of the utility model has the advantages that the branches of the high tree can be directly carried out the non-separation high temperature treatment. The utility model can satisfy the requirements of aspects that the high arbor tree species with long seeds mature period can double and breed polyploid for gametic chromosome, and the relationship between the development of the tree and the environmental change can be studied.