The invention provides a smart meter testing method. According to the smart meter testing method, a to-be-tested three-phase smart meter is connected with an electric energy data processing device which is arranged in a remote testing chamber. An accurate power P1 is obtained through multi-point accurate calculation on the data, and then a power P2 is calculated through the three-phase smart meter, and accuracy is obtained through comparison. The smart meter testing method realizes ultralow workload of a power supplying department and uninterrupted real-time verification. Therefore the smart meter testing method has advantages of effective time and labor saving, and high testing efficiency. Furthermore because uninterrupted real-time verification can be realized, relatively high loss of the power supplying department is prevented.