A mutual entity authentication method supporting rapid handoff, the method involving three security elements comprising two authentication elements A and B and a Trusted third Party TP, wherein the trusted third party TP is a trusted third party of the authentication elements A and B; the authentication element A comprises n authentication entities A1, A2,..., An, and the authentication element B comprises m authentication entities B1, B2,..., Bm, which comprise synchronization information; and all of the authentication entities in the same authentication element share one public key certificate or possess the same public key, and for any pair of authentication entities Ai(i=1, 2,..., n) and Bj(j=1, 2,..., m), the authentication method comprises the steps of: 1) transmitting, by the authentication entity Bj, an authentication activation message INI Bj to the authentication entity Ai, wherein INI Bj = R Bj ∥ ID B ∥ Text 1, wherein R Bj denotes a random number generated by the authentication entity Bj, ID B denotes an identifier of the authentication element B, and Text1 denotes a first optional text; 2) transmitting, by the authentication entity Ai, an access authentication request message AREQ Ai to the authentication entity Bj upon reception of the authentication activation message INI Bj, wherein AREQ Ai = R Bj ∥ R Ai ∥ ID A ∥ Text 2 ∥ TokenAB TokenAB = sS A R Bj ∥ R Ai ∥ ID A ∥ Text 2, wherein R Ai denotes a random number generated by the authentication entity Ai, ID A denotes an identifier of the authentication element A, Text2 denotes a second optional text, TokenAB denotes a token transmitted from the authentication entity Ai to the authentication entity Bj, and sS A denotes a signature of the authentication element A; 3) on receiving the access authentication request message AREQ Ai, verifying, by the authentication entity Bj, R Bj in AREQ Ai and R Bj in INI Bj for consistency, and if R Bj in AREQ Ai is consistent with R Bj in INI Bj, searching, by the authentication entity Bj, for a locally stored authentication result of the authentication element A verified by the trusted third party TP; if there is stored an authentication result of the authentication element A, going to step 4); 4) transmitting, by the authentication entity Bj, an access authentication response message ARES Bj to the authentication entity Ai, and calculating a shared master key between the authentication entities Ai and Bj, wherein ARES Bj = IRES TP ∥ R Ai ∥ Text 5 ∥ TokenBA TokenBA = sS B TokenAB ∥ R Bj ∥ R Ai ∥ Text 5, wherein Text5 denotes a fifth optional text, IRES TP denotes an identity authentication response message stored locally at the authentication entity Bj which comprises the authentication result of the authentication element A and an authentication result of authentication element B, TokenBA denotes a token transmitted from the authentication entity Bj to the authentication entity Ai, and sS B denotes a signature of the authentication element B; and 5) verifying, by the authentication entity Ai, the access authentication response message ARES Bj upon reception thereof. 1) transmitting, by the authentication entity Bj, an authentication activation message INI Bj to the authentication entity Ai, wherein INI Bj = R Bj ∥ ID B ∥ Text 1, wherein R Bj denotes a random number generated by the authentication entity Bj, ID B denotes an identifier of the authentication element B, and Text1 denotes a first optional text; 2) transmitting, by the authentication entity Ai, an access authentication request message AREQ Ai to the authentication entity Bj upon reception of the authentication activation message INI Bj, wherein AREQ Ai = R Bj ∥ R Ai ∥ ID A ∥ Text 2 ∥ TokenAB TokenAB = sS A R Bj ∥ R Ai ∥ ID A ∥ Text 2, wherein R Ai denotes a random number generated by the authentication entity Ai, ID A denotes an identifier of the authentication element A, Text2 denotes a second optional text, TokenAB denotes a token transmitted from the authentication entity Ai to the authentication entity Bj, and sS A denotes a signature of the authentication element A; 3) on receiving the access authentication request message AREQ Ai, verifying, by the authentication entity Bj, R Bj in AREQ Ai and R Bj in INI Bj for consistency, and if R Bj in AREQ Ai is consistent with R Bj in INI Bj, searching, by the authentication entity Bj, for a locally stored authentication result of the authentication element A verified by the trusted third party TP; if there is stored an authentication result of the authentication element A, going to step 4); 4) transmitting, by the authentication entity Bj, an access authentication response message ARES Bj to the authentication entity Ai, and calculating a shared master key between the authentication entities Ai and Bj, wherein ARES Bj = IRES TP ∥ R Ai ∥ Text 5 ∥ TokenBA TokenBA = sS B TokenAB ∥ R Bj ∥ R Ai ∥ Text 5, wherein Text5 denotes a fifth optional text, IRES TP denotes an identity authentication response message stored locally at the authentication entity Bj which comprises the authentication result of the authentication element A and an authentication result of authentication element B, TokenBA denotes a token transmitted from the authentication entity Bj to the authentication entity Ai, and sS B denotes a signature of the authentication element B; and 5) verifying, by the authentication entity Ai, the access authentication response message ARES Bj upon reception thereof.