The invention discloses a modified polystyrene material which comprises the following raw materials in percentage by weight: 65-90% of polystyrene resin, 8-30% of styrene-butadiene copolymer and 1-5% of liquid paraffin. The raw materials according to the formula are proportionally added, and a mixer is started to mix the raw materials for 5 minutes; and the mixture can be directly put into a common injection molding machine for production without drying the raw materials. The transparency of the modified GPPS (general purpose polystyrene) material disclosed by the invention remains the transparency of the original GPPS material, the elongation at break is enhanced from 2% to 5%, and the impact strength can be enhanced from 3KJ/m<2> to 15KJ/m<2>.