To characterize the effect of process variation of interconnect lines on single event crosstalk (SEC), Based on the equivalent RLC model for the interconnect line and the equivalent circuit for single event transient (SET), the ultimate process corner parameters of single event crosstalk (SEC) consideration with the process variations of the line are achieved by analyzing extreme difference and variance on the results of the designed orthogonal experimental, and then the mechanism of the effects of echnology node, ion energy, length of line on the ultimate process corner of SEC are also discussed. The results show that under condition of the combined effects of the coupling effects between the interconnect lines and the pulse propagation characteristics, and 45 nm above technology node, when the interconnect structure parameter fluctuates ±10%, the variation range of SEC is greater than 20%, and the relative variation increases with the increase of the current amplitude. Whereas there is no significant difference with the increase of the interconnect length. Under condition of 45 nm below technology node, although the voltage peak and noise area of SEC increase significantly, there is a decrease in the influence of interconnect process fluctuation on SEC, and the fluctuation of SEC increases with the increase of interconnect length.