The invention discloses an adaptive reclosing judgment method for a single-phase grounding fault of a power transmission line, and the method comprises the steps: collecting three-phase voltages and three-phase currents of one side of the power transmission line at two moments, and enabling the three-phase voltages and three-phase currents to serve as input; calculating the corresponding positive and negative zero-sequence voltage and current phasors through employing the measured voltages and currents at the two moments; Building equations for two types of possible faults (perpetual single-phase grounding fault and instantaneous single-phase grounding fault) based on a power transmission line distribution parameter model, and describing the relation of voltages and currents of two sides of the power transmission line, and obtaining two systems of nonlinear equations; taking the power potential, equivalent system impedance, fault distance and transition resistance of a measurement point opposite side system as unknown quantities, solving the built systems of nonlinear equations, respectively obtaining fault range finding results of the two systems of nonlinear equations, solving the ratio of the fault range finding results, determining that the perpetual single-phase grounding fault happens if the ratio is less than a threshold value, and locking the reclosing function, or else determining that the instantaneous single-phase grounding fault happens, and carrying out the reclosing.