Abstract: The effectiveness of temporary plugging is one of the important indicators for temporary plugging fracturing. However, there is currently a lack of methods to evaluate the effectiveness of the temporary plugging operation. Downhole fracture monitoring technology based on water hammer pressure waves can accurately capture the response of multiple fractures in the well after fracturing. Therefore, a temporary plugging effectiveness evaluation method (WHBEM) based on water-hammer pressure cepstrum was proposed in this paper. Firstly, based on the water hammer cepstrum response of downhole fractures before and after temporary plugging, a temporary plugging efficiency calculation methoccsd based on the change of the energy proportion of each cluster response was proposed. Secondly, a penalty function based on changing trend of the fractures–energy–response ratio was proposed to correct the temporary plugging efficiency of each fracture. Finally, the average value of the corrected temporary plugging efficiency of each fracture was taken as the temporary plugging effectiveness of this section, and an evaluation criterion for temporary plugging performance was established. The effect of nine temporary plugging fracturing sections in a carbonate condensate gas well in Xinjiang was evaluated using WHBEM. The results show an average temporary plugging effectiveness of 71% for the case well, with five sections rated as excellent and four sections as good, indicating overall excellent performance. Furthermore, the correlation coefficient between the calculation results of the WHBEM and Erf function is 0.57, demonstrating a consistent trend that aligns with the pressure increase observed during the temporary plugging operation in each stage. The research concludes that by quantitatively assessing temporary plugging efficiency through both the magnitude and trend of the water hammer response of each fracture, the WHBEM provides more objective and accurate evaluation results. This research can offer effective guidance for the real-time control of temporary plugging operations in the field.