The invention provides an inversion method and system of aerosol optical depth. The method includes: establishing an aerosol inversion lookup table and acquiring surface reflectance; on the basis of the WFV data of the GF-1 satellite, substituting the acquired surface reflectance, and looking up and interpolating the atmospheric parameters of the established aerosol inversion lookup table to obtain aerosol optical depth. The aerosol inversion lookup table is established by steps: calculating the volume ratios of four types of aerosol components on the basis of the data of a GEOS (Goddard earth observing system)-Chem atmospheric chemistry model, wherein the four types of aerosol include dust type aerosol, water-soluble aerosol, smoke type aerosol and sea salt type aerosol; taking the obtained calculation results as input parameters to establish the aerosol inversion lookup table by the aid of a 6SV1 radiation transfer equation. The surface reflectance is calculated on the basis of the surface bidirectional reflectance products of a foreign satellite MODIS. By inversion method, large-range aerosol monitoring can be realized quickly and accurately to provide a prerequisite for the remote sensing estimation of particulate matter concentration.