Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae) is an important pest worldwide and one of the major quarantine pests. Based on the current distribution points and environmental variables of P. operculella in China, this study used the maximum entropy model (MaxEnt) to predict the potential range and extent of P. operculella in China under current and future climate scenarios. The results showed that the total suitable area for P. operculella in China was approximately 363.6 km², accounting for 37.9% of the national land area. The high-suitability areas were mainly concentrated in the southwest and central plains. The key environmental variables affecting the potential distribution of P. operculella were the minimum temperature in the coldest month, the precipitation in the coldest season, seasonal temperature variation, and the maximum temperature in the hottest month. Under future climate scenarios, the potential suitable areas of P. operculella expand gradually, with the characteristics of some high-suitability and low-suitability areas transforming to medium-suitability areas in southern coastal provinces, and low-suitability areas expanding northward continuedly. This study provides theoretical guidance for the prevention and control of P. operculella by scientifically predicting its suitable regions and extents under future climate warming conditions.