The invention provides a miniaturized three-dimensional inverted T/R component. The upper end and the lower end of an H-shaped structural part are each provided with a cavity body and are closed by cover plates; the upper cavity body is internally provided with a power divider and a control circuit module by an LTCC (Low Temperature Co-Fired Ceramic) substrate, and the lower cavity body is internally provided with four T/R radio-frequency modules by an LTCC substrate; the LTCC substrates in the upper cavity body and the lower cavity body are communicated by an LTCC connector; the LTCC substrate in the upper cavity body are communicated with a radio-frequency joint and a multi-core micro rectangular joint which are led out downwards and penetrate through an opening of the lower cover plate and are respectively used as a power divider junction and a power supply control interface; the LTCC substrate in the lower cavity body is communicated with four radio-frequency joints which are led out upwards and are connected with a radiating antenna by an opening of the upper cover plate. The miniaturized three-dimensional inverted T/R component provided by the invention can be used for achieving the purposes of miniaturization, high reliability, easy repair and low cost and the like, and is suitable for thin-sheet type active phased-array antennas in engineering.