Downhole micro-seismic event real-time inversion location method based on grid search

The present invention provides a downhole micro-seismic event real-time inversion location method based on grid search. The method comprises: establishing a speed model in a space including a micro-seismic source under the well; performing P-wave and S-wave first arrival time pickup of the micro-seismic event; calculating the degree of polarization and the polarization direction of each channel recorded P-wave first arrival of the micro-seismic event; establishing a inversion target function, and performing the theory first arrival travel time from wave field forward modeling calculation grid points to an observation system; calculating a target function value, and determining the position of the seismic source; and calculating the three-dimensional spatial position coordinates of the seismic source. The method is fast in operation speed and high in efficiency; and moreover, the noise immunity is high, the micro-seismic event with low signal to noise ratio can be subjected to accurate micro-seismic source loc