A method for sensing abnormality of a personal blood glucose meter, wherein the personal blood glucose meter comprises: a sensor strip for collecting and supplying a blood sample, wherein the sensor strip includes an electron transfer mediator; an electrode unit including a plurality of electrodes to generate electric current based on a potential difference, the electrode unit comprising a flow sensing electrode for receiving a mixture of the blood sample and electron transfer mediator to generate first potential; an auxiliary electrode having a ground function; and a working electrode for receiving the mixture to generate second potential, whereby the working electrode is upstream of the flow sensing electrode; a microcontroller unit for measuring a current value generated from the electrode unit to determine whether a blood glucose value of the blood is normal or abnormal; a potential supply unit for supplying potential to the electrode unit; and a display unit for displaying a result value output from the microcontroller unit, the method comprising: supplying a reference potential from the potential supply unit to the flow sensing electrode and the working electrode; injecting the mixture to the flow sensing electrode and the working electrode; characterized in that the method further comprises the steps in the following order of: a) cutting off the supply of reference potential to the working electrode when blood inflow at the working electrode is sensed; b) cutting off the supply of reference potential to the flow sensing electrode when blood inflow at the flow sensing electrode is sensed; c) after the supply of reference potential to the flow sensing electrode is cut off, supplying the reference potential to the working electrode, and measuring a first current value generated from the working electrode; d) supplying the reference potential to the flow sensing electrode, and measuring a second current value generated from the working electrode; and e) comparing the first current value with the second current value to determine whether the personal blood glucose meter is normal or abnormal. a sensor strip for collecting and supplying a blood sample, wherein the sensor strip includes an electron transfer mediator; an electrode unit including a plurality of electrodes to generate electric current based on a potential difference, the electrode unit comprising a flow sensing electrode for receiving a mixture of the blood sample and electron transfer mediator to generate first potential; an auxiliary electrode having a ground function; and a working electrode for receiving the mixture to generate second potential, whereby the working electrode is upstream of the flow sensing electrode; a microcontroller unit for measuring a current value generated from the electrode unit to determine whether a blood glucose value of the blood is normal or abnormal; a potential supply unit for supplying potential to the electrode unit; and a display unit for displaying a result value output from the microcontroller unit, supplying a reference potential from the potential supply unit to the flow sensing electrode and the working electrode; injecting the mixture to the flow sensing electrode and the working electrode; a) cutting off the supply of reference potential to the working electrode when blood inflow at the working electrode is sensed; b) cutting off the supply of reference potential to the flow sensing electrode when blood inflow at the flow sensing electrode is sensed; c) after the supply of reference potential to the flow sensing electrode is cut off, supplying the reference potential to the working electrode, and measuring a first current value generated from the working electrode; d) supplying the reference potential to the flow sensing electrode, and measuring a second current value generated from the working electrode; and e) comparing the first current value with the second current value to determine whether the personal blood glucose meter is normal or abnormal.