The invention provides a photovoltaic power station low voltage ride through detecting system in a high altitude area. The photovoltaic power station low voltage ride through detecting system comprises a power grid, a power grid side transformer, a testing unit, a photovoltaic side transformer, a tested photovoltaic unit and an automatic detecting control system. The automatic detecting control system comprises a monitoring module monitoring a tested unit, a control module achieving automatic control, and a processing module analyzing detected data. Full-automatic design is adopted in the system control, the system automatically selects the matched reactive resistance combination and simulated failure time and adjusts a tapping switch to the corresponding position to finish reactive resistance matching, selects the simulated grid fault type and switches the position of a single-phase disconnecting switch to finish grid fault type matching according to the voltage drop depth and the simulated failure type input by a background tester, the low voltage ride through test is finished, the hardware protection function and the software protection function of the whole set of system can be matched, the self-diagnosis function is complete, and the stability is good.