The problem of reconstructing the location and type of a seismic source in a three-dimensional medium based on seismic observations is considered. The Time Reverse Mirror (TRM) method is used to solve this problem. Recently, the TRM method has been used in seismology to detect earthquake sources, in industry to detect defects in structures, in medicine to detect masses in human tissues, and in other fields. We were the first in the seismic industry to use TRM to simultaneously identify the type and location of the seismic source. Numerical modelling was carried out on three-dimensional synthetic models using finite difference techniques, which allowed us to develop an algorithm for reconstructing the seismic source type from observational data recorded on a free surface. Solution of this problem is impossible without using parallel architecture computing systems. Several parallelization techniques have been used to achieve high effciency of the parallel program. In particular, we use non-blocking MPI library functions and the domain decomposition technique to optimise the exchange of data between processes.