This paper presents a simplified description of the event evolution of the India power blackouts on the 30th and 31st of July in 2012. With the analysis of the technical causes leading to the difference in scale of system collapse between the 2blackouts，it is pointed out that the key cause of both events is the indirect transfer capability exceeded by cross-grid rerouting of large power flow due to lack of active control measures.While the centralized generator tripping and load shedding automatically triggered by the sudden loss event of transmission interface are the most effective emergency control measures for the prevention of similar blackouts，the economic rationality of which can be assessed from the viewpoint of risk reduction. From the perspective of emergency control technology，it is concluded that several fundamental measures need to be strengthened to ensure the effectiveness of the control，including research on fault identification criterion，analysis of mutual influence between control logic and system response，verification of adaptability of control effect to system operating conditions，and tightening up the operational management of emergency control measures.