For large-scale photovoltaic power station connected to medium-voltage grid, it is not proper to evaluate its power quality by traditional limitation in China. In this paper, it proposes testing technology and research in order to evaluate the power quality for large-scale photovoltaic power station according to latest photovoltaic standards. The tests will focus on flicker, harmonics, inter-harmonics and high frequency components. For voltage flicker under either continuous operation or switching operation, it gives one method which simulates the voltage fluctuation imposed by photovoltaic power station and calculates flicker emission on a fictitious grid, thereby avoiding the direct influence of the real voltage fluctuation of the grid at the measurement point on flicker. For current harmonics, interharmonics and high frequency components over continuous operation, it specifies the individual current components as sub grouped values in accordance with IEC 61000-4-7]. For the purpose of including the effect of voltage fluctuations during actual measurement, the choice of sub grouping method is applied.