In order to study the influence on the laser radar cross section (LRCS) measurement accuracy caused by atmospheric attenuation, begin with the LRCS measurement, the paper deduces the formula about the influence on the LRCS measurement accuracy caused by atmospheric attenuation, and finds the relation between atmospheric attenuation and LRCS measurement accuracy, that is, the LRCS measurement accuracy will go down at the condition of fore and after two different atmospheric attenuation, or it will go up. The visual simulation result is offered by MatLab simulation. Based on the typical atmospheric attenuation model, the paper illustrates the influence on LRCS measurement accuracy caused by atmospheric attenuation in light of two extreme atmospheric conditions, and offers some advice about LRCS measurement, which will be useful reference to the subsequent LRCS accuracy analysis and amendment.