The invention provides a file storage method, a file search method and a file storage system based on public-key encryption with keyword search. The method comprises: receiving a user file storage request sent from a data possessor, acquiring access control attribute information for access to a user file, security level parameters and a keyword set of the user file, generating a file attribute vector of the user file by means of the access control attribute information and the keyword set, acquiring a public-secret key pair used for encrypting the file attribute vector from a pre-generated key space, encrypting the file attribute vector by means of a public key in the public-secret key pair to obtain a ciphertext corresponding to the file attribute vector, and transmitting the ciphertext corresponding to the file attribute vector and a ciphertext of the user file to a preset storage server.