The invention provides ahorizon automatic interpretation method based on minimum seismic waveform unit classification. The horizon automatic interpretation method includes the steps that 1, seismic data of a target interval are subjected to continuous enhancement pretreatment; 2, coarse-mesh horizon interpretation is carried out on target horizon; 3, a preliminary interpretation result obtained inthe step 2 is used as a control point of horizon time, and top and bottom time windows containing a plurality of complete seismic waveforms are obtained by shifting upwards and downwards; 4, seismicdata in the time windows are divided into minimum waveform units; 5, characteristic values of the minimum seismic waveform units are extracted; 6, a minimum seismic waveform unit classification modelof a random forest is constructed; and 7, a horizon automatic interpretation result of the whole area is optimized. According to the horizon automatic interpretation method, the difficulty of optimizing a horizon automatic recognition algorithm is lowered, meanwhile professional constraints are imposed, the reliability of the horizon automatic interpretation result is effectively improved, and good application prospects are achieved.