Polyploid breeding is one of the important ways to create new varieties of forest trees and cultivate excellent germplasm. This article systematically reviewed recent advances in the induction of polyploidy in forest trees using physical, chemical, and biological methods both domestically and internationally. The physical method is represented by temperature change and mechanical damage, which is easy to operate, but has the problems of low induction rate and poor controllability. Colchicine treatment, as the representative of chemical methods, is the most mature and widely used method. It is the mainstream method for polyploid creation of forest trees. However, high chimerism incidence and prolonged recovery time post-treatment remain major drawbacks. Biological methods such as protoplast fusion and endosperm culture have developed rapidly in recent years, showing unique advantages in overcoming distant incompatibility and reproductive isolation and shortening the breeding cycle. At present, the research on polyploid breeding of forest trees mainly focuses on representative tree species such as poplar and eucalyptus, and homologous tetraploid and triploid plants have been successfully obtained through various methods. Polyploid plants exhibit giant organs, significantly improved fiber length and wood properties, as well as enhanced stress resistance. In the future, the collaborative application mode of the three methods should be further optimized, and the application potential of emerging technologies such as gene editing in polyploid creation should be actively explored to promote the development of forest polyploid breeding in the direction of high efficiency and precision.