A maintenance support system for a construction machine calculates the cumulative load of every component corresponding with the driving and working conditions of the construction machine by a load calculation means after simulating the driving and working conditions on the basis of production operating conditions by an operation simulation means, and forecasts the lifespan of the respective components by a lifespan calculation means on the basis of the cumulative load. Hence, a more accurate maintenance schedule can be established in comparison with a case where which component is to be maintained is determined on the basis of only the operating time.