Under surging conditions in the sea, the phase change and flow characteristics of two-phase fluids in plate-fin heat exchanger channels will change, which will affect the heat exchanger performance. In order to clarify the surging impact mechanism, a model for heat transfer characteristics of liquefied natural gas flow boiling in channel of plate-fin heat exchanger under surging conditions was established. Firstly, the mechanism of heat transfer and mass transfer of two-phase flow in the channels was analyzed, and the numerical model to simulate the flow and heat transfer under steady conditions was established; secondly, a model for reflecting the surging acceleration was added in the numerical model, which realizes the simulation of heat transfer charactersitics under surging conditions; the proposed model was verified based on the experimental data under onshore conditions. Based on the proposed model, the effects of vapor quality, frequency and amplitude of surging on heat transfer characteristics were analyzed. The results show that, the heat transfer coefficient increases with the increasing surging amplitude, while it decreases with the increasing surging frequency; as vapor quality increases, the influence of surging on heat transfer gradually changes from deterioration to enhancement; as vapor quality is within 0.2-0.8, the surging impact factor for the heat transfer coefficient is within 87.9%-110.0%. The effect of surging on time-average heat transfer coefficient changes with different conditions, representing a maximum deterioration of 5.0% and a maximum enhanceent of 2.0%. © All Right Reserved.