The invention discloses a dual component liquid silica gel for 3D printing and a printing method thereof. The liquid silica gel comprises a component A and a component B. The component A comprises following components in parts by weight: 100 parts of vinyl polysiloxane, 0.01 to 5 parts of a hydrosilylation catalyst, 1 to 10 parts of polyether polyol, and 1 to 10 parts of fumed silica. The component B comprises following components in parts by weight: 100 parts of vinyl polysiloxane, 1 to 50 parts of hydrogen containing polysiloxane, 0.01 to 5 parts of a hydrosilylation inhibitor, 1 to 10 partsof polyether polyol, and 1 to 10 parts of fumed silica. During the printing process, the thickness of the liquid silica gel does not change, the structure is not deformed, an onsite heat treatment isnot needed, only post sectioned thermosetting moulding is needed, the printing technology is simplified, and the printing cost is reduced. The liquid silica gel does not contain any organic solvent or photosensitive component, is very safe and nontoxic, and 3D products prepared from the liquid silica gel can be applied to fields, which have high safety requirements, such as children toys, food, medicines, and the like.