<p>Fire and explosion incidents occur concurrently. Due to the sensitivity of steel strength to temperature, the ability to withstand the explosion of steel frames will be damaged in a fire after the explosion. The joints are the key to steel structures. Studying the impact of steel frame joints under the combined effects of explosion and fire is of great significance. This article established a finite element model of steel frame joints using ANSYS/LS-DYNA to analyze the dynamic response of steel frame joints under the combined action of explosion and fire. A method was employed to study how explosions and fires interact with steel joints, focusing on the combined effects of heat and structural deformation. The analysis results indicate that when an explosion occurs first and then a fire occurs, the larger the explosion load, the earlier the joint is destroyed during the heating process. The fire resistance of the joint decreases, and the possibility of buckling failure of the column flange increases. When a fire occurs first and then an explosion occurs, the higher the temperature, the lower the peak pressure of the explosion. The explosion resistance performance of the joint decreases. At 687 ºC, the bearing capacity of the joint is almost 0. The situation of fire-first scenario causes more severe damage to joints than the situation of explosion-first scenario. Therefore, it is recommended to use high-strength steel for steel joints to enhance the explosion resistance performance and apply paint to the joint area to improve the fire resistance performance.</p>