The invention discloses a method for achieving a transformer substation video monitoring system on basis of an ONVIF protocol. The method relates to an IP camera, a network switch, a video processing unit, a storage server, an administration client and a monitoring client, wherein the pan-tilt control signal input end, the OSD configuration signal input end and the equipment configuration control signal input end of the IP camera are connected with the pan-tilt control signal output end, the OSD configuration signal output end and the equipment configuration control signal output end of the video processing unit respectively. The ONVIF protocol is extended in the transformer substation video monitor station end system. OSD configuration provides the function that the clients can control and configure screen information of the IP camera, and according to the function, various types of OSD configuration parameters such as characters, data and time can be displayed on a screen. A shielding and detecting function can analyze whether a picture is shielded, and an ONVIF analysis module expression language can be used for describing configuration information of a shielding engine module, judging whether a detected area is shielded and determining whether a video shielding phenomenon occurs.