[en] The several thermal hydraulic design codes used for the pulse reactor developed by Nuclear Power Institute of China (NPIC) independently are presented. They are the natural circulation flow analysis code (MC-FLOW), the core thermal hydraulic analysis code (MC-THAS) and the pulsed reactor transient analysis code (MC-TRAN). These codes can meet the requirements and are verified on the basis of the prototype pulsed reactor. The verification shows these codes can be used for the engineering design of Xi'an pulsed reactor with full confidence