The invention discloses a method for calculating pneumatic parameters of a two-dimension trajectory correction projectile with a fixed rudder. The method comprises the steps of constructing the two-dimension trajectory correction projectile; building an entity model of the two-dimension trajectory correction projectile; building a mesh model of the two-dimension trajectory correction projectile; importing the mesh model of the two-dimension trajectory correction projectile into Fluent software; and performing Fluent software setting and numerical calculation. By utilizing the method for calculating the pneumatic parameters, the relatively accurate pneumatic parameters of the correction projectile can be quickly obtained, and a wind tunnel test does not need to be carried out for verifying the accuracy of pneumatic calculation data, so that a large amount of time and project funds can be saved; and it is verified that the accuracy of a calculation result can be ensured through wind tunnel test data.