An aurora borealis simulation device and an aurora generating method are provided, which relates to the technical field of light simulators and includes: a simulation device main body and an aurora simulation component. A projection window is provided on the simulation device main body. The aurora simulation component comprises: a light-emitting unit; a fixing frame fixedly mounted on an inner wall of the simulation device main body; a radiator arranged on the fixing frame and assembled corresponding to the light-emitting unit; a first light-transmitting component of which one part is provided on the fixing frame and the other part extends toward a side of the projection window and is located between the projection window and the light-emitting unit, and a second light-transmitting component fixedly mounted on the simulation device main body and located within the projection window.