Based on comprehensive research and analysis of the generation mechanism, instrument, signal processing and characteristics of debris flow infrasound, the key scientific and technical problems of debris flow infrasound warning were reviewed. The debris flow infrasound has its distinct characteristics in peak frequency, frequency range and time-frequency variation, which can be identified from the infrasound of other natural hazards. The short-time Fourier transform(STFT), wavelet transform (CWT), Wigners-Ville distribution (WVD) and the Hilbert Huang transform (HHT), etc. for analyzing methods of infrasound signals are usually used, and the HHT is more suitable for the processing of debris flow infrasound signal. The infrasound warning of debris flow can be divided into occurrence warning, type and scale warning and position warning, etc. The occurrence warning recognition algorithm is based on the SON part signal, and the classification warning algorithm is based on the SBO part signal, and the occurrence warning and type and scale warning cannot be realized simultaneously. Sensor array setting, applicability of location algorithm and mountain environment are the main influencing factors of position warning precision. By limitation of the mechanism of debris flow and field infrasound observation, the theoretical analysis and numerical calculation of debris flow infrasound mechanism are in the exploratory stage. There are no accurate and reliable numerical relationships between the infrasound characteristics and formation, movement elements of debris flow. In the future, the simulation experiment and numerical simulation should be carried out, combined with the synchronous monitoring of the debris flow warning system, to realize the quantitative infrasound warning of debris flow.