Embodiments of the present disclosure provide a blood glucose monitoring device and a monitoring method thereof, which can reduce the influence of the oral environment on the measurement accuracy. The blood glucose monitoring device comprises: a housing a micro-current stimulation module connected to two electrodes and generating a current, the two electrodes being located on a surface of the housing and the current stimulating the parotid gland of a user through the two electrodes to produce fresh saliva a saliva glucose acquisition module configured to acquire a glucose concentration in the saliva a control processing module configured to control the micro-current stimulation module to work and to obtain a blood glucose concentration value from the glucose concentration.
