Urban　waterlogging　due　to　extreme　precipitation　presents　an　increasingly　serious　challenge.　Pooling　of　large　volumes　of　surface　water　can　result　in　flooding　of　underground　spaces.　However,　there　remains　limited　studies　on　flooding　of　underground　spaces　through　the　application　of　hydrological　and　hydrodynamic　models.　This　study　examined　flooding　in　an　urban　district　of　Zhengzhou　City,　China　during　an　extreme　rainstorm　event　on　20th　July,　2021.　An　integrated　simulation　model　of　regional　surface　and　underground　spaces　was　established　based　on　InfoWorks　Integrated　Catchment　Model　(ICM)　software.　The　generalized　reservoir　and　hydraulic　connectivity　methods　were　used　to　simulate　underground　spaces.　Factors　contributing　to　the　initiation　and　development　of　flooding　of　underground　spaces　were　analyzed.　The　results　showed　that　underground　waterlogging　was　less　conducive　to　alleviation　of　surface　water　ponding.　The　advantages　of　the　generalized　reservoir　method　were　shown　to　be　its　relative　simplicity　and　feasibility,　whereas　that　of　the　hydraulic　connection　method　was　its　detailed　representation　of　underground　flooding.　Both　the　cumulative　quantity　of　rainfall　and　rainfall　intensity　were　shown　to　have　important　effects　on　underground　inundation.　The　results　of　this　study　can　help　to　improve　urban　stormwater　forecasting　and　warning　systems,　and　provide　a　theoretical　basis　for　regional　disaster　prevention　and　reduction.　©　2023　China　Water　Power　Press.　All　rights　reserved.