The invention discloses an atmospheric parameter lookup table generation method based on curve fitting, and is mainly used for generating an atmospheric parameter lookup table in a photoelectric three-dimensional scene. The method comprises the following implementation process that: setting a curve fitting simulation parameter; dividing the altitude height interval of a detector; calculating the altitude value of the detector; calculating the maximum effective value of path length; dividing the subinterval of the path length; calculating the path length value of the path length interval; calculating an atmospheric parameter; calculating a fit curve parameter; generating an atmospheric parameter lookup table, i.e., an atmospheric transmissivity look up table and an atmospheric path radiation lookup table. The method has the advantages that the calculation accuracy of the atmospheric parameter is kept, the calculation amount of the atmospheric parameter is reduced, the generation time ofthe atmospheric parameter lookup table is shortened and the generation efficiency of the atmospheric parameter lookup table is improved.