The types of pests and diseases, host plants, degree of damage and affected areas of ecological forests were investigated in Fengxian District, Shanghai through observation and investigation methods and fixed-point investigation methods. The results showed that (1) There were 12 main types of diseases in the ecological forest of this area, among which 2 types of diseases had a higher degree of damage, accounting for 16.67%. There were 7 types with a severity of ++, accounting for 58.33%. There are 3 types with a degree of harm of +++, accounting for 25.00%. (2) There were 20 species of major pests in ecological forests, belonging to 19 families and 7 orders. Among them, there were 4 species of Lepidoptera, 3 species of Coleoptera, 6 species of Homoptera, 2 species of Hymenoptera, 2 species of Orthoptera, 2 species of Thioptera and 1 species of Diptera. The main pests with a degree of damage of +++ included Spodoptera litura, Monema flavescens, Ascotis selenaria, Anoplophora chinensis and Mesoneura rufonota. The affected plants included tree species such as Paulownia fortunei and Camphora officinarum, and the damaged parts were leaves, trunks and branches. In response to the occurrence of pests and diseases in this area, it is proposed to remove weeds and whitewash tree trunks. Adopt strategies such as using low-toxicity, highly effective and low-residue biological or chemical pesticides to control pests and diseases, in order to reduce the frequency of pest and disease occurrence. This study provides a reference for the prevention and control of major diseases and pests in ecological forests in relevant areas.