Corrosive gases in the environment can corrode the metal components of connectors, thereby reducing their high-speed transmission performance. This paper investigates the impact of corrosive environment on the signal integrity of connectors. Firstly, a connector contact model with rough contact areas was established based on digital filtering technology, and a uniformly corrosion products was created on the contact area. Then, the effects of corrosive substance thickness, conductivity, and relative dielectric constant on the signal integrity of the connector were studied. The conclusion is that increasing the relative dielectric constant is beneficial for high-speed signal transmission only when the film resistance is high. According to the conductivity and thickness of corrosive substances, their impact on signal integrity can be divided into three degradation levels. The increase of degradation level seriously affects the signal integrity of the connector: increasing the maximum return loss and impedance, reducing the minimum insertion loss, reducing the eye height and width of the eye diagram, and increasing jitter. By measuring the signal integrity parameters of connectors after salt spray/SO2 accelerated corrosion experiments, it was found that when the corrosion time was less than 96 h, the impact of corrosive substances on signal integrity belonged to the degradation Level-1, while when the corrosion time was 144 h, it belonged to the degradation Level-2.