In the process of handling public emergencies such as natural disasters, the data required by the government is diverse and cross-departmental, and a single data exchange model is far from sufficient to meet emergency response needs. This paper proposes a method for decomposing task data requirement lists based on ontology and generating task data based on a graph model. By using metadata to support the linking of task data requirement lists and data resources, it supports the construction of task data spaces and the efficient sharing of information, addressing the challenge of cross-domain data sharing in emergency situations.