Abstract: The effect of grain cultivation purposes on the application of biological pesticides by rice farmers has implications for the moderating role of environmental awareness in the context of the green development of agriculture and rural areas. Based on 1103 micro-survey data of rice farmers in Hubei Province in 2021, the influencing and moderating mechanisms of the application behavior of biological pesticides by rice farmers were analyzed from the perspectives of food rationing and profits. The theoretical analysis framework of rice farmers’ behavior incorporated environmental utility. The Logit model was used to analyze the influence and heterogeneity of the purpose of grain cultivation and environmental awareness on the application behavior of biological pesticides in rice farmers. The study found that: 1) There were significant differences in the application behavior of biological pesticides by rice farmers with different purposes of grain cultivation, namely, those oriented towards food rationing and those oriented towards profit making. Profit-oriented rice farmers were more inclined to use biological pesticides. 2) Environmental awareness had a significant positive impact on rice farmers’ application of biological pesticides. Pesticide cognition significantly promoted the application of biological pesticides by profit-oriented rice farmers, while environmental protection attitudes had a more significant impact on the application behavior of biological pesticides by rice farmers more inclined to food rationing. 3) Significant differences in the application of biological pesticides were observed among rice farmers with different capital endowments. Environmental protection attitude had a more significant impact on the application of biological pesticide by rice farmers with high level of education, while a positive moderating effect of pesticide cognition existed among rice farmers with low level of education. Environmental protection attitude had a more significant impact on the biological pesticide application behavior of rice farmers with low-income level, and the moderating effects of pesticide cognition and environmental protection attitude also existed among rice farmers with low-income level. Environmental protection attitude had a more significant impact on the application behavior of biological pesticides by rice farmers with a low degree of land fragmentation, whereas a positive moderating effect of pesticide cognition existed among rice farmers with high degree of land fragmentation. Based on this, this study proposes formulating corresponding promotional measures for biological pesticides according to the planting purposes of rice farmers, formulating phased training on biological pesticides, improving rice farmers’ cognition of biological pesticides, strengthening their environmental awareness, and building an agricultural technology exchange platform to promote the application of biological pesticides by rice farmers.