Method for detecting fluid content of different types of tight sandstone reservoirs

The invention discloses a method for detecting fluid contained in different types of tight sandstone reservoirs. Comprising the following steps: performing full-angle anisotropic rock physical acoustic wave testing on different types of tight sandstones to obtain waveform data corresponding to transmission cracks at different angles, picking up head wave amplitude and first arrival in waveforms, and calculating amplitude anisotropy parameters (AA), longitudinal wave anisotropy parameters (epsilon) and slowness anisotropy parameters (SNA) of the different types of tight sandstones; corresponding elastic parameters can be calculated in combination with the rock density; (AA-epsilon) rock physical quantity layout is constructed, and corresponding threshold values are set to select crack-pore type compact sandstone saturated gas reservoir rocks; constructing a rock physical quantity layout (SNA) and setting a corresponding threshold value to select pore type compact sandstone saturated water reservoir rock; a (mu