The invention provides a method for realizing RFID (Radio Frequency Identification) two-way authentication by use of a physical no-cloning technology. The method comprises the steps that a reader/writer sends a command for requesting authentication to a label; the label sends IDS stored by the label to the reader/writer as response after receiving the command; the reader/writer verifies the authenticity of the sent IDS, calculates the values of K(+)r and ID(+)F(IDS(+)r) and sends the calculation results to the label; the label verifies the authenticity of the calculation results sent by the reader/writer, obtains a random number r through calculation of K(+)r (+)K and further calculates F(IDS(+)r); the label verifies the accuracy of the ID through calculation of ID(+)F(IDS(+)r)(+)F(IDS(+)r); the label calculates the values of G=P(G) and G=P(G) if the ID is accurate and then sends the values of G(+) G(+)r and the G(+)F(r) to the reader/writer; the reader/writer verifies the authenticity of the values sent by the label again; the reader/writer obtains G through calculation of the G(+)G(+)rG(+)r; further, the reader/writer verifies the accuracy of a message G=G(+)F(r) (+)F(r); and finishing the authentication process if the message is accurate. According to the method, the problem that safety defects exist in two-way authentication between the label and the reader/writer in an RFID system is solved, and the cost of the label end is reduced.