The invention relates to a pseudo-random number generation method based on chaotic function combination selection, comprising the following steps: S1, initializing n chaotic functions f1, f2, f3-fi, fn to generate n initial function value sequences r1, r2, r3-ri-rn, where n is greater than or equal to 3; S2, simplifying each of the n initial function value sequences r1, r2, r3-ri-rn into an initial pseudo-random number sequence b1, b2, b3,-bn which only contains 0 or 1 through calculation; S3, dividing the n initial pseudo-random number sequences b1, b2, b3-bn into M levels cj; And S4, carrying out item-by-item selection on the pseudo-random number sequences with the same level or low level through the high-level pseudo-random number sequences so as to generate an ultimate pseudo-random number sequence bf. According to the pseudorandom number generation method, the new pseudorandom number sequence is generated through mutual item-by-item selection among the chaotic functions, and compared with the pseudorandom number sequence generated through column-by-column selection in the prior art, the combined selection method is higher in precision.