The invention relates to a photovoltaic power station dynamic reactive response performance site testing method. Test points in the method are selected to be at the positions of photovoltaic power station combining points; voltage changes of buses in a photovoltaic power station are achieved by adjusting a main transformer tap. The method includes the steps of measuring output of active power and reactive power of the photovoltaic power station; confirming a detection device; adjusting an on-load transformer tap to enable the voltage of the combining points to meet the voltage deviation requirement; recording the active power output by the current station with the luminance keeping at 400 watt/square meter to be P0; setting the photovoltaic power station to work in the end voltage control mode; adjusting the on-load transformer tap to observe the reactive motion of the power station; analyzing test results to calculate photovoltaic power station dynamic response performance indexes. The photovoltaic power station dynamic reactive response performance site testing method solves the problems that when photovoltaic power station dynamic reactive response measurement is carried out, the volume of a testing device is limited, and a modeling testing method is too complex are solved, and a photovoltaic power station station-stage reactive response capacity testing method system at present is perfected.