The invention provides a high-precision position return and dangerous area alarm method and device. The method relates to the technical field of substation safety, and comprises the following steps: issuing a position acquisition instruction to acquire position information of a handheld terminal, and performing geographic coordinate precision correction on the position information of the handheldterminal by using a Big Dipper high-precision difference technology to acquire third positioning information; acquiring geographic position information of the transformer substation, constructing a transformer substation model, acquiring position coordinates of the transformer substation in the transformer substation model, and determining a safety area in the transformer substation model; and determining position coordinates of the hand-held terminal in the transformer substation model based on the third positioning information, and determining whether the worker is in the safe area based onthe position coordinates of the hand-held terminal in the transformer substation model and the safe area in the transformer substation model. Through the method provided by the invention, the construction safety of the transformer substation can be improved, and favorable information is provided for improving the safety production management level of the transformer substation.