The invention discloses a SaaS (Software as a Service) platform based on cloud computing. The platform comprises a cloud platform control end, preset software examples, at least one user, a service layer, a facility layer and a storage layer, the service layer is used for facing the users, receiving requests of the users and feeding back information to the users, the facility layer is connected with the service layer and used for receiving requests of the service layer and opening the software examples according to the requests, and the storage layer is connected with the facility layer and used for storing data mirroring generated when the software examples are used by the users. The platform has the advantages that the high-maturity SaaS platform based on Open Stack simultaneously supports a PC (personal computer) and various mobile terminals and is high in expandability, safe, reliable and low in cost, by the aid of the platform, the users can seamlessly use services of the software examples only through web pages without contacting with the software examples, software cracking is fundamentally prevented, and fairness of a software industry is maintained.