The invention discloses a novel photovoltaic power station passive anti-islanding protection method, which belongs to the field of electric power systems and automation technologies thereof. The novel photovoltaic power station passive anti-islanding protection method calculates power frequency fault impedance and power factor change, judges whether an independent load-carrying small island of a photovoltaic power station and a joint load-carrying large island of the photovoltaic power station and a transformer substation appear comprehensively through an impedance criterion and a power factor criterion, and trips off a corresponding grid-connection switch once the island is detected, so as to protect the safety of operation maintenance personnel and equipment. The novel photovoltaic power station passive anti-islanding protection method is applicable to a mode that a large-scale photovoltaic power station is merged into a power grid transformer substation in a centralized manner, and can effectively solve the island protection problem under two conditions that the photovoltaic power station has an island independently and the photovoltaic power station and a transformer substation bus have an island together.