A multi-axis piezoelectric stress-sensing device, a multi-axis piezoelectric stress-sensing device polarization method, and a piezoelectric sensing detection system thereof are disclosed. The piezoelectric sensing detection system is used for a machining tool. The multi-axis piezoelectric stress-sensing device includes a piezoelectric sensing film, a first electrode, a second electrode, a third electrode, and a fourth electrode. The piezoelectric sensing film has four corners. The first electrode, the second electrode, the third electrode and the fourth electrode are located at the four corners of the piezoelectric sensing film, and at least one electrode is used to polarize another electrode according to at least one polarization direction.