High salinity frequently causes inhibition and even failure in anaerobic digestion. To explore the impact of increasing NaCl concentrations on biogas production and reveal the role of repair factors in response to high salinity stress, the present research examined the effect of ammonium acetate and betaine as exogenous repair factors on the activity of microorganisms under high‐salt conditions. High salinity wastewater with and without repair additives were compared. The cumulative methane production significantly increased and the methane concentration increased by approximately 30%. The results showed that the repair factors were efficient to relieve the effect of a high‐salt environment on the anaerobic microbial flora, thus considerably reducing the salt‐induced inhibition of anaerobic digestion.