The utility model relates to an on-line monitoring instrument for electrical equipment. The on-line monitoring instrument comprises a video acquisition sending device, an insulation connecting device and an image displaying device. The on-line monitoring instrument has the secure and reliable effects. Short-distance observation on equipment electrical portions at various positions can be realized under the circumstances that the security of the personnel and the equipment is ensured; and data image information is collected to provide accurate information for equipment repairing. Therefore, the provided on-line monitoring instrument has the high practicability.