Abstract: For circular stilling well with inclined inflow and lateral discharge conditions，based on semi- empirical formula method of turbulent jet division，mechanism of water force under submerged jet could be analyzed，and expressions of maximum velocity along jet and time-average force in impact area could be deduced，but complex turbulent flow characteristics could not be fully revealed.Numerical simulation based on turbulence theory could better describe time-averaged flow and turbulence characteristics in flow field of circular stilling well.According to region shape，spatial and time domain were dissected and separated，and three-dimensional closed solvable Reynolds stress equations were established from statistical evolution of turbulent N-S equation with irregular boundary.Results of analysis showed that the model was feasible and effective，which ccould provide reference for similar engineering design and optimization.