The invention provides an establishment method of a pornographic detection model, comprising the following steps: extracting video characteristics and audio characteristics from a sample audio-video object with marked information; according to the marked information, training respectively models for various audio characteristics and video characteristics in the sample audio-video object, and thencalculating fusion parameters among the models by virtue of a weighed average fusion method based on seqencing; in the value interval of an ergodic parameter orness of the weighed average fusion method based on seqencing, calculating corresponding fusion parameters for the values of the parameter orness; calculating the effect of fusion parameters by the sample audio-video object; and then selecting the fusion parameters with the best effect as the fusion parameters among the models. Compared with relevant methods in the prior art, the pornographic detection model of the invention synthetically uses the video characteristics and the audio characteristics, thus greatly improving the detection accuracy.