Abstract: The present application belongs to the field of architecture, and specifically provides a multi-story modular house and its connection assembly; the connection assembly includes a connector, a first connection module for connecting with the first box, and a second connection module for connecting with the second box, and the connector has a connection part, a shear resistance part and a calibration part connected in sequence. The connection part is used to connect with the first connection module. The second connection module is equipped with a calibration hole and a grouting chamber. The shear resistance part is a tooth-like structure, and the tooth-like structure is used to connect with the irrigation The grouting materials in the grouting chamber are meshed; the first box and the second box of the multi-story modular house are connected by the above-mentioned connection assembly.