Abstract: Warning-source traceability provides basis for disease early warning in solar greenhouse vegetables. Using disaster chain-styled theory and plant epidemiological theory, disease warning-source traceability problems and disaster mitigation modes by cutting the disaster chain were systematically analyzed. The disease warning-source traceability model was tested for cucumber downy mildew in solar greenhouse conditions. The model took into account the multi-warning-sources of disease early warning under solar greenhouse conditions and their effects on the interpretation ways of disease early warning. The instance of cucumber downy mildew under solar greenhouse conditions was tracked and analyzed using the disease warning-source traceability model. The study shows that overcast, rainy, snowy and foggy weather conditions are the warning-sources of cucumber downy mildew. The spatial and temporal variability of solar greenhouse environment was detected, and then warning-sources information was determined. The model could provide decision-making support for obviating downy mildew disease situations in solar greenhouse cucumber.