The work aims to study the effect of optimized laccase mediator system (LMS) on the strength and surface hydrophobicity of the pulp molded packaging material with LMS used to treat poplar CTMP pulp. The change in tensile strength, contact angle, fiber surface lignin structure and fiber surface topography, etc. was analyzed by means of orthogonal test, infrared spectrum analysis and scanning electron microscope. The best way to treat poplar pulp with laccase mediator system was A2B1C4D3E2. The best reaction conditions were: 1.68 g of pulp; 6 of pH, 60 ℃ of reaction temperature, and 90 min of reaction time by constant air introduction. When poplar CTMP pulp is treated by LMS under such conditions, part of residual lignin in the pulp is oxidized, bonding between fiber and fiber is strengthened, and the tensile strength and hydrophobic property of pulp molded packaging materials are improved.