Tree-shaped fin exhibits an excellent performance in balancing the strong and weak heat flow in latent heat exchangers, which renders higher solidification efficiency and more uniform temperature distribution. Based on the enthalpy-porosity method, a transient model of the solidification heat transfer in the heat exchangers with five tree-shaped fins are established and numerically analysed. The solidification behaviours of the phase change material (PCM), including liquid fraction and temperature evolution, in tree-shaped heat exchanger are investigated and compared with corresponding ones. The results indicate that the tree-shaped fin introduces more uniform solidification front and yield a higher solid fraction. Compared with the traditional longitudinal fins, the efficiency of heat exchanger with four-level tree-shaped fins increases by 53%. In terms of solidification efficiency, the tree-shaped fin configuration with four-level is considered as the optimal fin configuration. The initial temperature difference and the thermal conductivity of fins largely determine the solidification trend of the PCM in the heat exchanger. Compared with the width ratio, the heat exchanger with larger length ratio stores more energy during the phase change process. (C) 2019 Elsevier Ltd. All rights reserved.