Cucumber wilt a cucumber disease caused by Fusarium oxysporum f. sp. cucumerinum. Clarifying the environmental conditions under which cucumber wilt disease infects cucumbers is of great significance for the prevention and control of cucumber wilt disease. In order to investigate the effect of different pH conditions on the growth status of cucumber wilt pathogen, this experiment configured PDA and PDB media with different pH gradients, observed and measured the growth rate and colony morphology of cucumber wilt pathogen in different media, in order to explore the most suitable pH for the occurrence of wilt disease. The results showed that the optimal pH for PDA culture medium was 5.5-9.0 (actually 4.5-6.5), and the morphology of the bacteria also varied at different pH levels. In the PDB medium, the growth of the pathogen under pH 11 treatment was the worst compared to other pH treatments, indicating that the colony was not suitable for growth in the PDB medium under alkaline conditions. Therefore, Fusarium oxysporum is suitable for growth within the pH range from 4.5 to 6.5.