The invention discloses a method for expressing human interleukin 7 in eucaryotic host. When the eucaryotic host is pichia X-33, the method comprises the following steps of: (1) cloning an IL-7 gene of human; (2) building an eucaryotic expression vector; (3) transforming recombinant vector to the eucaryotic yeast host; and (4) expressing a rIL-7 protein in the yeast host. A prior method for expressing IL-7 by using prokaryotic host escherichia coli is changed, and a method for expressing IL-7 through eucaryotic host pichia is searched out, thereby ensuring an IL-7 biologic activity and obtaining a large amount of stable protein.