An increasing number of record-breaking extreme precipitation events worldwide has had an incalculable socioeconomic impact, challenging the ability of cities to recover and reconstruct after disasters. The key to the effectiveness of post-disaster recovery and reconstruction lies in the rational investment and allocation of reconstruction funds. However, few studies have examined the effectiveness of reconstruction fund planning in improving urban recovery and reconstruction from a post-disaster indirect economic loss assessment perspective. This study uses an improved input-output model to evaluate the degree of change in indirect economic losses under multidimensional reconstruction fund planning (funds' amount, the time efficiency of investment, and funds allocation) to measure the effectiveness. We exemplify this through a case study: a record-breaking extreme urban flood and its reconstruction planning occurred in Henan Province, China, in July 2021. The results indicate that (1) under the premise of ensuring sufficient financial input, improving the input time efficiency is a decision with a higher benefit-cost ratio, which can improve the effectiveness by 140%. (2) If funds are guaranteed, improving time efficiency is better than adding extra funds, and when both reach 80%, additional funds may not further improve the effectiveness. (3) The funds need to meet at least the recovery production needs (about 45% of direct economic losses); otherwise, the funds cannot be used to improve fortifications. The study results will provide theoretical and practical support for urban decision-makers to develop efficient and rational recovery and reconstruction programs.