Abstract: In the calculation of fluid parameters for the primary and secondary circuits using the system analysis and calculation code, adopting the two-fluid model to calculate the void fraction and fluid temperature can yield more accurate prediction results. An important parameter that needs to be determined in the two-fluid model is the interphase heat transfer coefficient of bubble condensation. In previous studies, most of the experiments studied on the interphase heat transfer were based on the parameters obtained from the condensation characteristics of subcooled boiling vapor bubbles to calculate the interphase heat transfer coefficient. In this experiment, the interphase heat transfer coefficient was calculated by rapidly increasing the pressure on the saturated vapor bubble generated on the heating plate and floating in a large space to cause the bubble to condense. The pressure range of the experimental conditions was 0.10-2.53 MPa, and the Jacob number of the experiment was 5.46-17.41. The experimental results demonstrate a gradual thickening of the boundary layer surrounding the steam bubble during the condensation process, accompanied by a decrease in the interphase heat transfer coefficient. The experimental results of the interphase heat transfer coefficient were compared with those obtained from direct contact condensation and subcooled boiling bubble condensation, revealing that the impact of bubble shape and vapor-liquid interface roughness on the interphase heat transfer coefficient is more pronounced than the influence of the wall effect. The bursting of bubbles is not observed during the condensation process, and regardless of their initial shape, all bubbles eventually transform into spherical shapes and dissipate as the condensation progresses. A processing method for the interphase coefficient in the rapid pressure change process was proposed in the experiment. A method was employed to calculate the interphase heat transfer coefficient of bubble condensation caused by pressure increase. The purpose of its usage is to mitigate the impact of bubble compression on the computation of interphase heat transfer. The expression of the Nusselt number was fitted, with an average error of 23.5%. The majority of the data falls within a margin of error of 30%, suggesting that the experimental results are highly reliable. The fitted relationship was verified and compared with the experimental data, and the average prediction error was 21.32%. The interphase heat transfer coefficient fitted in this study was obtained by eliminating the bubble compression effect. However, since the experimental bubble’s diameter change is influenced by both interphase heat transfer and bubble compression, the resulting error range remains within acceptable limits.