The present invention discloses an electric energy metering device state assessment method, device and system. The method comprises: collecting user load motion information at each power consumption day in N continuous power consumption days, wherein N is an integer of being not smaller than 2; obtaining a distance measurement coefficient of each two adjacent power consumption days according to each load motion information and the Mahalanobis distance measurement calculation correlation, wherein the Mahalanobis distance measurement calculation correlation is shown in img file='DDA0001231353030000011.TIF' wi='697' he='89', wherein d is a distance measurement coefficient, xi is the load motion information at the (N-1)th power consumption day, and xj is the load motion information at the Nth power consumption day; determining whether each distance measurement coefficient is larger than an early warning coefficient or not, if each distance measurement coefficient is larger than the early warning coefficient, determining that the power consumption day corresponding to the distance measurement coefficient is an abnormal power consumption day, and determining that the user electric energy metering device state is abnormal; or else, determining the power consumption day corresponding to the distance measurement coefficient is an normal power consumption day, and determining the electric energy metering device state is normal. The electric energy metering device state assessment method, device and system need few data, are easy to perform data collection and are easy to realize the state assessment.