This article conducts laboratory accelerated corrosion tests on simulated coastal atmospheric corrosion of 2A12-T4 aluminum alloy plates, simulating the impact of corrosion on the fatigue characteristics of aluminum alloy plates throughout the entire coastal atmospheric corrosion process from initial pitting to later erosion. Based on the principle of equivalent fatigue life degradation, an accelerated equivalent relationship between 2A12-T4 aluminum alloy plate accelerated corrosion and atmospheric corrosion is established. The research results show that the fatigue life degradation law of 2A12-T4 aluminum alloy after accelerated pre corrosion in laboratory is consistent with that of atmospheric pre Corrosion fatigue life degradation law, which is characterized by "rapid decline period"+"platform period". The first 144 hours of accelerated corrosion in the laboratory are approximately equivalent to the effect of corrosion on fatigue life in the first year of actual atmospheric environment; After 144 hours, every 36 hours of accelerated corrosion (3 cycles of immersion) is approximately equivalent to the effect of 2 years of corrosion on fatigue life in actual atmospheric environments.