We present an energy management scheme for the power-over-fiber system used in the electric power industry. The scheme dynamically adjusts output power of the system by tuning the driven current of the laser, according to the power consumption of the external load, which is deduced by the output current and voltage of the photovoltaic cell. In addition, an auxiliary power is employed to increase the output power and improve the dynamic response of the system. Experiments were made in which the static response, dynamic response, and the stability of the scheme were tested. The results show that our scheme can automatically control the output power of the system corresponding to the external load, which leads to the alleviation of the working temperature and potentially increases the reliability of the system and even prolongs the lifetime.