The ever‐growing demands for energy supply have put great stress on environment protections. Photo‐electrochemistry (PEC) is a repaid developing technique which can directly transform solar energy into chemical compounds and have been regarded as a promising strategy to solve the energy and environmental problems. However, the biggest restriction is the fast recombination of photo‐generated charge carriers which greatly limits the PEC efficiency. In recent years, introducing external‐field into PEC system have been proved to be a powerful method to enhance the PEC performance and attracted more and more attentions. In this review, we summarized the remarkable progresses in external‐field enhanced PEC reactions including mechanical stress field, thermal field, electrical field, magnetic field and muti‐field coupling. The enhancing principles of different external‐fields have also been systemically discussed. Furthermore, the challenges and outlook of the external‐field enhanced PEC reactions are presented.