Abstract: In the practice of project management, construction schedule management which concerns the benefits of project investment is one of key indices. Because of complexity, dynamics and uncertainty in the process of construction, the schedule prediction and control during the construction implementation are extremely difficult.This study quantizes the uncertainty and randomness of complicated factors in the enforcement of construction schedule on the basis of reliability theory and probability theory. Reliability prediction model for single congeneric factor influence has been established and applied to engineering case. The model can take scientifically and quantitatively predictive analysis to the short-term complicated changes during the implementation of construction schedule, thus evaluating the risk of construction duration more accurately and controlling construction schedule more effectively.