<p>Thermal runaway of lithium batteries occurs frequently with the rapid development of the new energy industry, and the inhibition methods for it are still limited. Dry water fire extinguishing agents with a core–shell structure have a good cooling effect, which can quickly cool the combustion while extinguishing the flame. It makes the dry water inhibit the thermal runaway of the lithium battery, which has certain feasibility. To determine its efficiency, dry water was prepared, and the extinguishing experiments on ternary lithium-ion battery thermal runaway were carried out. Results showed that dry water has a positive effect on restraining the thermal runaway of ternary lithium batteries. It can effectively suppress and weaken the flame after the explosion of the lithium battery and successfully interrupt the spread of the lithium battery thermal runaway. Under the release pressure of 0.4&#xa0;MPa, the inhibition effect of 8 mass% ammonium dihydrogen phosphate modified dry water is the best, and the maximum temperature of the No. 2 lithium battery can be controlled within 60℃. The main mechanism of dry water to inhibit it is to suppress and weaken the flame and form a protective layer to absorb thermal radiation and continue cooling.</p>