<p>This study presents a numerical simulation on bubble dynamics and heat transfer during saturated flow boiling in a parallel microchannel structure. The saturated-interface-volume (SIV) method was combined with Hardt and Wondra method to model the phase change process, while a coupled level set and volume-of-fluid (CLSVOF) method was employed for interfacial tracking. The bubble dynamics and the corresponding heat transfer characteristics were investigated under different heat fluxes. Results indicated that the bubble behaviors showed significant differences in parallel channels due to the uneven flow distribution. In channels with larger mass fluxes, the bubbles exhibited greater velocities but smaller volumes when exiting their respective channels. The heat transfer coefficient distributions along the flow direction were closely related to the bubble motion. At the upstream of the bubble, the heat transfer coefficient at the upper channel wall and lower channel wall showed significant differences, while they were comparable at the downstream of the bubble. The heat transfer was enhanced due to the bubble passage in each channel. The increase of heat flux could accelerate the bubble motion, meanwhile the oscillations of mass flux in the parallel channels were also enlarged. On a contrary, the local heat transfer coefficients at channel walls were decreased under higher heat flux.</p>