Photocatalysis can generate free radicals to degrade and mineralize organic pollutants by absorbing solar energy, which has the advantages of green, energy saving, and pollution-free. Photocatalysis is considered to be the most promising advanced oxidation technology. The current research focuses on improving the degradation efficiency of photocatalytic technology. The use of external field-assisted methods, such as electric field and ultrasonic field, can further improve the photocatalytic efficiency by improving the mass transfer efficiency of the solution, suppressing the carrier recombination, and improving the free radical yield. The research progress and application status of the five external fields assisted in photocatalytic degradation of organic pollutants are reviewed, including electric field, thermal field, microwave field, ultrasonic field and magnetic field. The main mechanism of external field to improve photocatalytic degradation efficiency is highlighted. The advantages and disadvantages are summarized, and the problems faced in practical applications are presented. The future research and development directions are prospected.