The durability and the accuracy are the critical issues for the design of auto-balance device, which have been well discussed in the literature. However existing solutions were incomplete, they have some defects such as their complicated structure, lots maintenance, poor serviceability and poor balance accuracy. In this paper, we proposed a novel scheme to enhance the durability and the accuracy significantly, which includes three main points: The first, we extract fundamental wave signal with discrete Fourier transform. The second, we adopt electric magnetic drive. The third, we employ planetary gear drive with small teeth difference. The experiment results show that our scheme can achieve satisfactory balance accuracy, which validates our analysis. All the results are obtained by over 1000 hours continuous experiments.