The invention relates to a random number generation method and a random number generator. The method comprises the steps that a plurality of physical random sources perform digital processing on a generated physical signal and sends a digital signal obtained by processing to an S box; the S box performs nonlinear replacement processing on the digital signal and outputs a replacement processing result to an XOR module; the XOR module performs XOR processing on the replacement processing result and outputs an XOR processing result to a post-processing module; and the post-processing module eliminates a deviation and a dependency relationship in the XOR processing result and outputs a random number. According to the random number generation method and the random number generator provided by embodiments of the invention, the problem of XOR attack of the physical random sources is effectively solved; and even if an attacker attacks an input of a physical random source in the XOR position, an input of post-processing still contains information of the random source because the S box has the characteristic of a confusion property.