The present invention provides a method for preparing a gallium oxide semiconductor structure and a gallium oxide semiconductor structure obtained thereby. The method comprises: providing a gallium oxide single-crystal wafer (1) having an implantation surface (1a) (S1); performing an ion implantation from the implantation surface (1a) into the gallium oxide single-crystal wafer (1), such that implanted ions reach a preset depth and an implantation defect layer (11) is formed at the preset depth (S2); bonding the implantation surface (1a) to a high thermal conductivity substrate (2) to obtain a first composite structure (S3); performing an annealing treatment on the first composite structure such that the gallium oxide single-crystal wafer (1) in the first composite structure is peeled off along the implantation defect layer (11), thereby obtaining a second composite structure and a third composite structure (S4); and performing a surface treatment on the second composite structure to remove a first damaged layer (111), so as to obtain a gallium oxide semiconductor structure comprising a first gallium oxide layer (12) and the high thermal conductivity substrate (2) (S5). In the gallium oxide semiconductor structure formed using the above method, the first gallium oxide layer (12) is integrated with the high thermal conductivity substrate (2) to effectively improve the thermal conductivity of the first gallium oxide layer (12).