The invention discloses a certificate-free combined secret key generation and application method. The method comprises the following steps: S1, a server end generating an elliptical curve, skm and pkm, and issuing parameters of the elliptical curve and the pkm; S2, a client generating ID, xID and PKuk, and uploading the ID and the PKuk to the server end; S3, the server end generating SKID, PKID, rID and PKrID; S4, the server end generating PKE, SKE and PKS; S5, the service end issuing the SKE to the client, and broadcasting the ID, the PKE and the PKS; S6, the client generating SKS through the xID and the SKE, and decrypting encryption information through the SKE, and signing verification information through the SKS; and S7, a general client encrypting decryption information and verifying signature information through the PKS. The method provided by the invention solves the problems of non-repudiation of sum bumps, linear collusion and individual signature of a combination public key technology and the like.