The present invention relates to an object trajectory estimation technology. A system for three-dimensional (3D) object trajectory estimation according to an exemplary embodiment of the present invention includes: an infrared sensor frame installed in a target space area; an acoustic sensor module installed in the target space area; and a processing unit configured to estimate a trajectory of an object within the target space area on the basis of pieces of data generated from the infrared sensor frame and pieces of data generated from the acoustic sensor module.