The invention discloses a high-void-ratio cold-mixed epoxy resin mixed material and preparation method thereof. The mixed material is prepared from the following raw materials in parts by weight: 100 parts of mineral aggregates, 0-5 part of mineral powder, 5-6 parts of an epoxy resin binder, 0-0.5 part of rubber particles, 0-0.3 part of an anti-ageing agent, wherein each 100 parts of the mineral aggregates include the following mineral aggregates in parts by weight: 10-15 parts of a mineral aggregate with a particle size of 0-3mm, 55-65 parts of a mineral aggregate with a particle size of 5mm-10mm and 25-30 parts of a mineral aggregate with a particle size of 10mm-15mm; the epoxy resin binder contains a component A and a component B, the component A is an epoxy resin emulsion, the component B is a curing agent corresponding to the epoxy resin emulsion, and the component B is 30%-50% of component A in percentage by mass; the particle size of the rubber particles is 1mm-3mm. The mixed material has effects of excellent mechanical property, high stability, excellent high-temperature stability and low-temperature performance, high water stability and shearing resistance, high void ratio and water permeability coefficient and low scattering loss and is applicable to a lower layer of a pavement layer of a cement concrete bridge deck.