The invention discloses a precise reservoir prediction method based on waveform classification and retrieval under forward constraints. The method comprises the steps of selecting an effective range and converting large-region multi-phase spread into micro-region single phase spread; dividing a reservoir in the single phase spread into different types, and summarizing sedimentary characteristics of different types of reservoirs and post-stack seismic reflection characteristics; simulating a typical waveform of each type of reservoirs via wave equation forward modeling; performing frequency expanding treatment on the single phase spread seismic data by using well control mixed phase wavelet deconvolution; performing primary waveform classification on a single phase spread range by using a non-supervision neural network classification method; and reconstructing a waveform model trace, re-classifying the waveforms, and implementing waveform retrieval. According to the method provided by the invention, a corresponding relation between the reservoir types and the waveforms is built by wave equation forward modeling, and the waveforms are primarily classified and then retrieved to achieve precise prediction of the different types of reservoirs in the phase spread, so that the method is the effective and rapid precise prediction technology for recognizing the different types of reservoirs in the same phase spread in a small range.