Objective This study aims to provide a novel synergistic combination for the control of apple alternaria blotch.Method The inhibitory activities of 7 chemical fungicides， fermentation metabolites of antagonistic strain SJ1606 and their combinations against Alternaira alternata were determined by mycelium growth rate method.Result The 7 chemical fungicides had strong inhibitory activity against the pathogen. Among them， tebuconazole， difenoconazole and propiconazole had the best inhibitory effect on the pathogen， with EC₅₀ values of 0.21， 0.30 and 0.81 μg/mL， respectively， followed by pyraclostrobin， mancozeb and azoxystrobin. Carbendazim had the poorest antifungal effect， with EC₅₀ of 15.03 μg/ mL. The EC₅₀ of the fermentation supernatant and the crude extracts of the fermentation supernatant were 2.38 μL/mL and 0.53 μL/mL， respectively. The combinations of the crude extracts and mancozeb， pyraclostrobin showed synergistic effects， and the volume ratios of 6：4 and 7：3 reached the maximum toxicity ratios， which were 1.39 and 1.41， respectively.Conclusion This study can provide basic data support for the update of control measures of apple alternaria blotch and reduction of chemical fungicides.