Abstract: System simulation is one of the important methods to assist the system design.How to combine them in order to improve the efficiency of the design process is a challenging research topic.To this end,we proposed a novel system design and simulation integration method based on SysML,which is the standard modeling language for systems engineering,and the multi-domain simulation modeling language Modelica.Specifically,firstly,we analyzed and compared the metamodels of SysML and Modelica based on the Meta-Object Facility(MOF);then,according to the metamodel of Modelica,we constructed the M-Design profile by extending from SysML;finally,we defined the mapping rules between the two languages so that the automated transformation between the system design model in SysML and system simulation model in Modelica can be achieved.We used the tank system as a case study to illustrate the integration process.