In paper, at first, a structured model of smart electricity meters is established and the main factors that lead to smart electricity meters errors is analyzed and determined, that is the change of reference voltage of AD converter with temperature. Then, the mathematical models of CMOS bandgap reference and AD converter affected by temperature are established. And by using the commonly used point product energy measurement algorithm, the influence and relationship between the reference voltage of smart electricity meter and temperature is studied and analyzed. The relationship curve between the error change of smart electricity meter and the temperature change with time is given through experiments. Finally, according to the accuracy level of smart electricity meter , the suggestions on temperature reference conditions of automatic calibrating conveyor line of smart electricity meters is proposed.