As a kind of tall moving obstacle, wind turbines have an inevitable impact on weather radar performance. The analysis of electromagnetic scattering characteristics of wind turbine is significant for the identification of wind farm disturbing and the evaluation of influence on weather radar. In this paper,considering the effect of the dielectric constant for cylindrical blade on the radar cross section (RCS), an analytical formula of the RCS calculation for cylindrical blade is proposed based on numerical theory, and the results are validated by simulation. Meanwhile, a real blade is modeled by using software UG in consideration of airfoil section. Therefore, the electromagnetic scattering characteristics including RCS and timefrequency domain analysis are established. Simulation results demonstrate the validity of the modelling method in comparison with the measured data. Finally, an analytical formula of real blade′s RCS is adapted with a certain range.