This invention discloses a nucleic acid aptamer AS1411 modified DNA tetrahedron. The preparation method includes the steps of (1) binding an AS1411 sequence to the 5′ terminal of any DNA single-strand in a DNA tetrahedron, synthesizing the DNA, dissolving obtained DNA powder with ddH2O; (2) measuring an absorbance of the DNA and then calculating a total volume of the four single strands; (3) pipetting the DNA obtained in step (1) according to the calculation results in step (2), mixing the DNA with a TM buffer, mixing the mixture uniformly with vortex vibration, and performing a PCR progress. The preparation method is simple. The produced product can effectively solve the problem that the unmodified DNA tetrahedron cannot enter the nucleus and the problem that the AS1411 cannot carry drugs directly.