Taking advantage of the characteristics of high electromechanical coupling effect, no electromagnetic interference and simple mechanism of the piezoelectric vibration energy harvesting technology, a symmetrical self-powered synchronous electric charge extraction (SSP-SECE) circuit is proposed in this paper, which uses complementary transistors to realize synchronous switching control, and the peak value self-detection can be realized by the steering diodes and detecting capacitors. The rationality of the circuit scheme is tested by modeling and simulation using Multisim software, and the validity of the circuit is verified by experiments. The experimental results show that the load resistance power of the optimized SSP-SECE interface circuit is 4.23 times higher than that of the standard energy harvesting circuit, and 23.02% higher than that of the SECE circuit as a whole.