The utility model provides an on-site invasion alarm system for an oil tank. The on-site invasion alarm system comprises a camera array, a microphone array, a motion detection module, a control module, a storage module, a radio frequency card reader, a short message alarm module and a mobile terminal, signals sent to the motion detection module through the camera array and the microphone array areused for excluding animals and non-living objects. Management personnel are excluded through the radio frequency card reader, irrelevant personnel are finally recognized, invasion models are stored,and alarm short messages are sent, so that the management personnel effectively monitor the conditions of personnel near the oil storage tank, the irrelevant personnel are prevented from getting closeto the oil storage tank, and accidents are avoided.