Abstract: The UO₂ dual bubbles model under bubble internal pressure was proposed, and the stress distribution of fuel particles under different intra-bubble distances was calculated by using the finite element method. The effects of intra-bubble distance, bubble radius and bubble internal pressure on the interaction of bubbles were discussed. The results show that when the interaction of bubbles is considered, stress concentration occurs and locates at the fuel particles between bubbles. The rate of stress concentration is related to the ratio of intra-bubble spacing to bubble radius (spacing radius ratio, SRR) but unrelated to the bubble internal pressure. When SRR equals 1, the stress concentration rate is about twice that when the interactions of bubbles are ignored. When the sizes of bubbles are different, the stress concentration occurs primarily at the fuel near the small bubbles.