The invention discloses a white polycarbonate composition with high toughness and high glow wire initiation temperature and a preparation method thereof. The white polycarbonate composition comprises the components in parts by weight: 96.0-99.8 parts of polycarbonate resin, 0.1-5.0 parts of a toughening agent, 0.01-5.0 parts of a white colorant, 0.01-2.0 parts of an antioxidant and 0.01-0.8 part of other auxiliary agents. The polycarbonate resin having specific viscosity average molecular weight is selected for ensuring mechanical strength of the composition and high flowability during thin wall molding; the added preferred toughening agent can supplement the toughness of the composition and reduce the influence on the glow wire initiation temperature to a greatest extent; especially, selected titanium dioxide after special treatment cannot affect the mechanical properties and the glow wire initiation temperature resistance while providing white. The prepared composition has relatively high toughness and glow wire initiation temperature resistance, is suitable for white products, and is especially suitable for occasions having relatively high use environmental requirements.