The existing digital energy meter test standard was developed on the basis of that of electronic energy meter, the test items do not fully consider the characteristics of digital energy meter. To improve the operating stability of digital energy meter, this paper established a comprehensive monitoring platform and developed a digital meter with 0.01 accuracy based on adaptive all-phase algorithm. Then several new test methods for digital meter were proposed on the foundation of the platform. Finally some prototype digital meters were evaluated according to test item. The experiment results shows that these new test items are able to guarantee the accuracy of digital energy meter in complex conditions, the digital energy meter which pass these new test items can be used to measure energy of long-term accuracy.