The invention belongs to the technical field of cloud computing security, and discloses a searchable encryption method with a hidden retrieval mode and a cloud server, and the method comprises the steps that a data owner is used for building an index and an encrypted file set, outsourcing the encrypted file set and the index to the cloud server, and generating search trap door information at the same time; a data user submits a keyword query request to the data owner; the server C2 is mainly used for providing help for the cloud server C1 and assisting the C1 to execute retrieval; and the cloud server C1 is used for executing retrieval operation under the assistance of the server C2 according to the trap door information submitted by the data owner, and returning a matching result to the user. According to the method, a retrieval mode can be hidden, and searching of multiple keywords is supported at the same time. According to the invention, an expected safety target can be achieved. In the retrieval process, the server selects a random polynomial with proper times, generates a result polynomial by utilizing addition homomorphism, and ensures that the search result polynomial doesnot leak any other information except for a retrieval result required by a user.