Abstract: To provide a 3D data acquisition device, a 3D data acquisition system, and a 3D data acquisition method for an elevator which are capable of improving measurement accuracy of 3D point group data on an inside of a shaft. The 3D data acquisition device for the elevator includes: a housing that constitutes an outer shell; and a plurality of 3D distance imaging sensors which are provided in the housing so as to directly face each of a plurality of side walls of a shaft of the elevator on a horizontal projection plane and which acquire 3D point group data. According to the configuration, measurement accuracy of 3D point group data on the inside of the shaft can be improved.