Abstract: It is proposed a new method of controlling cracks of pouring mass concrete for raft foundation of nuclear power plants.Software ANSYS is used to set up a 3-D finite element numerical simulation model for pouring concrete of raft foundation.A scheme of monitoring the temperature strain is worked out,optimized curing curves are designed,and the curing measures are adjusted dynamically during the curing period.At present,this method is already applied in raft foundation for 6 nuclear islands of different nuclear power plants,there are no obvious cracks on the concrete after stripping.This method has a bright future of application and popularizing.