This article presents a terahertz detector utilizing a field effect transistor constructed from a Co₃Sn₂S₂/MnBi₂Te₄ heterostructure. By effectively coordinating the three-dimensional microstructure and external fields, the detector achieves high sensitivity for applications within the 6G communication frequency band at ambient temperature. Specifically, at a frequency of 0.1 THz, the photoresponsivity (Rv) is measured at 2.6×10⁶ V/W, which represents a 26-fold enhancement compared to conventional Golay Cells. Furthermore, the equivalent noise power (NEP) is recorded at a remarkably low value of 75 pW/Hz1/2.