Abstract: This paper applies three methods,i.e.,analytical solution,numerical method and electrical network,to analyse and contrast three-dimension and two dimension flow,and discusses the difference and handling in the parameters fitting,groundwater quantity and level forecast.Finally,authors calculate three-dimension and two dimension flow models of drainage in Yuanbaoshan open-pit mine,and advances that the drainage of large-drawdown,large-discharge is an obvious three-dimension flow process and so three-dimension flow model must be applied.