For linear block code which takes the matrix interleave in channel coding, a new method is proposed to estimate blindly the interleave parameters. It determines firstly the multiple of interleave depth by constructing data matrix, then does one-dimensional hypothesis for the interleave offset. At last, two-dimensional hypothesis for the interleave depth and interleave width is taken in order to deinterleave the intercepted data, and to achieve the blind estimation of all interleave parameters. The method is applicable to any case of matrix interleaver for interleaver depth estimation, especially for the kind that the interleaver depth is not equal to an integer multiple of the code length which has not been studied so far. Simulation results show that, the detection probability can reaches 98% even though the bit error rate is 0.001. Meanwhile, the algorithm has a fast detection speed no matter what the interleaver depth is.