The present invention discloses a software security verification method, a device, and a system, and relates to the communications field, so as to resolve a problem in the prior art that security verification on a VNF packet increases a VNF instantiation delay and reduces VNF instantiation performance. In a specific solution, after a first device receives an instantiation request of a VNF, the first device performs security verification on a stored VNF packet of the VNF when or after starting to instantiate the VNF according to the instantiation request of the VNF, and the first device sends first result information to a second device when security verification on the VNF packet of the VNF succeeds. The first result information includes information that security verification on the VNF packet of the VNF succeeds. The present invention is applied to software security verification.