The invention discloses a power plant outlet line single-phase self-adaptive reclosing method. Through introducing two fault property diagnosis methods with different principles, and according to a fault property distinguishing result of a faulty line, the reclosing is shut under a permanent fault, so as to ensure that the faulty line is not reclosed; under a transient fault, the influence of thefactors such as attenuation of a submerged current, and the cooperation of the reclosing with the corresponding protection is comprehensively considered, so that the optimal reclosing time of the power plant outlet line is determined; and when the diagnosis result is that the fault is diagnosed as a permanent fault by one method and the fault is diagnosed as a transient fault by the other method,the influences of the attenuation of the submerged current, the cooperation of the reclosing with the corresponding protection, and the secondary impact of the reclosing under the permanent fault on the system are considered, so that the optimal reclosing time is determined. The invention provides a technical support for the self-adaptive reclosing of the power plant outlet line, and ensures the stable operation of the power system to the greatest extent on the basis of improving the continuity and reliability of the power supply.