The work aims to explore the safety of self-heating packages due to volatile gases, plasticizer migration, etc. during self-heating based on the concerns about the safety of self-heating food from consumers. In this work, six brands of self-heating food packages purchased from market were selected to determine the types of gases generated during the self-heating process, their emissions and residues in the food, and analyze the hazard during self-heating by comparing with the corresponding limit values. It was found that 17 harmful gases were detected during the self-heating process, but the emission levels were all under the standard of air pollution and inhalation toxicity limits. But during self-heating, the food might be mixed with trichloromethane, which was detected more in the olive oil than rice. With the extension of heating time, the residual level of trichloromethane increased first and then decreased, and finally got close to the limit value. No residue of plasticizer was found after self-heating. The study suggests that the main potential safety issue in self-heating food is the residues of trichloromethane. Direct contact between the food and the gases released in self-heating should be prevented. This study provides data support for analysis of hazards during self-heating of self-heating foods and lays a foundation for further research and development of self-heating foods.