In order to improve the energy conversion performance and conversion efficiency of the bistable piezoelectromagnetic complex energy harvester(BPEEH), a novel tristable piezoelectromagnetic complex energy harvester(TPEEH) is proposed on the basis of the typical BPEEH, which has a novel electromagnetic power generation device to further constitute the tristable system compared with the traditional BPEEH. In this paper, a mathematical model of the TPEEH structural device is developed and numerical analysis is performed to obtain the potential energy change function of the harvester system. Based on this, the effects of external excitation frequency, magnet spacing, and circuit load resistance on the output voltage and power of this collector were further verified experimentally. The experimental results show that the TPEEH collector has a maximum output voltage of 6.348 9 V under this condition when the magnetic distance is 16 mm, the external magnetic spacing is 26 mm, and the external excitation frequency is 10.2 Hz, while the collector obtains a maximum output power of 0.08 W when the external load resistance is 500 Ω. Therefore, compared with the conventional BPEEH collector, the TPEEH collector has the advantages of lower acquisition resonant frequency, wider acquisition band, and higher output voltage and power, which further improves the energy conversion performance and efficiency.