The invention relates to the field of communication, and more particularly relates to a placement method of a virtual network function based on a genetic algorithm. The method comprises the followingsteps: S1, querying a system cache to judge whether a deployment result of a current type of SFC request exists, and if yes, skipping to step S4; if not, skipping to step S2; S2, sequentially selecting physical nodes and instances to be placed for a VNF in a service chain in combination with the calculation steps of the genetic algorithm; S3, mapping a virtual link of the SFC according to the VNFplacement situation obtained in step S2 to guide sequential transmission of data traffic; and S4, allocating requested physical resources to the SFC according to the deployment result. In the placement method provided by the invention, the resource relationship between the deployed VNF instances and the actually running VNF is clarified, and the count of VNF instantiation is limited to simulate the limited resources owned by an virtual network operator; and the processing of the SFC request is implemented by using as few VNF instances as possible, thereby prompting the rational use of the underlying physical resources of the entire network, and reducing the cost.