A method for joint secondary synchronization signal detection and frame timing synchronization, characterized by comprising following steps: generating local secondary synchronization sequences SSC1 and SSC2 according to a secondary synchronization sequence generation method and a sector number of a cell group, wherein the SSC1 and SSC2 can be denoted as the 168x 62 matrixes respectively, dividing the SSC1 and SSC2 into SSC1_n and SSC2_n respectively according to 168 rows, wherein n is an index of multiple-frame average, setting n=0; converting received time domain signals to frequency domain to obtain secondary synchronization signals S1 and S2 to be detected; carrying out a cross correlation operation on said S1 and S2 with SSC1_n and SSC2_n to form inner products, then combining inner product results to obtain correlated vector sets [S1,SSC1_n]+[S2,SSC2_n] and [S1,SSC2-n1+[S2,SSC1_n], and letting P1_n=P1_n-1 + [S1,SSC1_n] + [S2,SSC2_n], P2_n=P2_n-1 + [S1,SSC2_n] + [S2,SSC1_n], wherein P1_-1 and P2_-1 are empty sets; selecting a maximum value P of absolute values of correlation values in the P1 n and P2 n, and judging whether the maximum value P is greater than a preset threshold Tmax; if yes, taking the index of the maximum value P as a cell group number, and completing one frame timing synchronization by judging whether the maximum value occurs in P1_n or P2_n, wherein if the maximum value P occurs in the P1, the S1 and S2 are the former half frame and the latter half frame respectively, or else, the S1 and S2 are the latter half frame and former half frame respectively; if not, comparing the absolute values of the correlation values in the P1_n and P2_n with a threshold Tccv, selecting the secondary synchronization sequences corresponding to the correlation value of which the absolute value is not less than the Tccv in the P1_n and P2_n as new secondary synchronization sequences SSC1_n and SSC2_n, increasing the index by 1, and then carrying out step, and then carrying out step. generating local secondary synchronization sequences SSC1 and SSC2 according to a secondary synchronization sequence generation method and a sector number of a cell group, wherein the SSC1 and SSC2 can be denoted as the 168x 62 matrixes respectively, dividing the SSC1 and SSC2 into SSC1_n and SSC2_n respectively according to 168 rows, wherein n is an index of multiple-frame average, setting n=0; converting received time domain signals to frequency domain to obtain secondary synchronization signals S1 and S2 to be detected; carrying out a cross correlation operation on said S1 and S2 with SSC1_n and SSC2_n to form inner products, then combining inner product results to obtain correlated vector sets [S1,SSC1_n]+[S2,SSC2_n] and [S1,SSC2-n1+[S2,SSC1_n], and letting P1_n=P1_n-1 + [S1,SSC1_n] + [S2,SSC2_n], P2_n=P2_n-1 + [S1,SSC2_n] + [S2,SSC1_n], wherein P1_-1 and P2_-1 are empty sets; selecting a maximum value P of absolute values of correlation values in the P1 n and P2 n, and judging whether the maximum value P is greater than a preset threshold Tmax; if yes, taking the index of the maximum value P as a cell group number, and completing one frame timing synchronization by judging whether the maximum value occurs in P1_n or P2_n, wherein if the maximum value P occurs in the P1, the S1 and S2 are the former half frame and the latter half frame respectively, or else, the S1 and S2 are the latter half frame and former half frame respectively; if not, comparing the absolute values of the correlation values in the P1_n and P2_n with a threshold Tccv, selecting the secondary synchronization sequences corresponding to the correlation value of which the absolute value is not less than the Tccv in the P1_n and P2_n as new secondary synchronization sequences SSC1_n and SSC2_n, increasing the index by 1, and then carrying out step, and then carrying out step.