The invention discloses a novel surface sizing agent for blueprint base paper. The novel surface sizing agent contains the following components in parts by weight: 2-8 parts of styrene, 10-60 parts of acrylic resin, 0.2-15 parts of a neutralizing agent, 100 parts of acrylate resin, 0.10-0.65 part of a defoaming agent and 240-1465 parts of water. The novel surface sizing agent for the blueprint base paper has the characteristics of safety, environmental friendliness, good film-forming property, high curing speed and outstanding water resistance, and the defects of common surface sizing agents for the blueprint base paper are solved.