The HFSS electromagnetic simulation model of a complete transmission path structure was established, analyzed the signal integrity of complete transmission path in high frequency and acquired the return loss of complete transmission path based on the model. The effect of external diameter of via, inner diameter of via and height of via to signal integrity of complete transmission path were studied. And external diameter of via, inner diameter of via and height of via as design parameter, the parameters of different levels in the 9 groups combined return loss of complete transmission path with different via were analyzed by analysis of variance using orthogonal design method. The results show that with the height of via, external diameter of via and inner diameter of via increases, the return loss of complete transmission path also increases; when the confidence is 95%, the influence of height of via and external diameter of via to signal integrity of complete transmission path is highly significant, and the effect of inner diameter of via to signal integrity of complete transmission path is not significant.