As the fact that schedulers usually utilizing resources re-allocation and improving resource-utilization efficiency in coping with project delay caused by risk events，a stochastic simulation evaluation method based on duration controllability of network schedule was put forward. This method took the resource allocation and utilization of margin of the activity as controllable indicators， and considered different constructability of measures reaction to different occur time of risk events. Through the stochastic simulation of each risk events occur time， delay of activity duration and effect of the risk reaction，the distribution of project duration was simulated which was utilized to evaluate the rationality of the network schedule. A case indicates that，compared with traditional simulation evaluation methods such as duration-based and factors-based Monte-Carlo simulation， simulation results of the duration controllability-based is more reasonable.