In order to construct risk management indicators in case of overdraft in payment system, we need to understand the correlation of transfer and risk factors, and then quantify the risk by simulation. This study is using the payment data in Payment System to investigate the risk factors of transfer. Then we predict transfer values by regression and simulation by risk factors variation to understand the opportunity of overdraft with some indicators. Finally, increase and decrease 10% risk factor value to do the pressure test for the toughness in payment system.