Embodiments of the present application provide an automatic focusing method and a PTZ camera. The method is applicable to the PTZ camera and comprises: calculating a current target object distance from a lens of the PTZ camera to a monitored target monitoring plane based on a pre-established spatial object distance parameter; wherein, the spatial object distance parameter contains a spatial plane equation of a reference monitoring plane; the reference monitoring plane is an equivalent plane of the target monitoring plane; searching in a preset relation table based on the current target object distance, a current magnification of the PTZ camera, determining a position information corresponding to a focus motor of the PTZ camera, the preset relation table including the relationship of the object distance, the magnification and the position information of the focus motor, and driving the focus motor to a position corresponding to the determined position information. Embodiments of the present application are applied to realize fast automatic focusing of the PTZ camera.