The invention discloses a Terahertz endoscope applicable to intestinal tract lesion detection and a detection method. The Terahertz endoscope comprises a combined tube body, a Terahertz signal enhanced module, a Terahertz detection module and a real-time imaging module, wherein the combined tube body is inserted into the intestinal tract, and mainly consists of a sleeve tube, a sleeve head and a semispherical glass cover; the Terahertz signal enhanced module mainly consists of a tunable laser and an optical fiber arranged in the sleeve tube; the Terahertz detection module mainly consists of a Terahertz wave detector, a Terahertz wave emitter, a first stainless steel metal wire and a second stainless steel metal wire; the first stainless steel metal wire and the second stainless steel metal wire are arranged in the combined tube body; the real-time imaging module mainly consists of an image processing and transmission circuit board, a power supply wire, a video signal wire, an LED (Light Emitting Diode) cold light source and a COMS (Complementary Metal Oxide Semiconductor) camera; and the power supply wire, the video signal wire, the LED cold light source and the CMOS camera are arranged in the combined tube body. The Terahertz endoscope and the detection method have the advantages that the accurate detection on the intestinal tract lesion in the early stage of the intestinal tract lesion is realized; the detection accuracy and the detection sensitivity are improved; the rich information is obtained; the structure is compact; the operation is convenient; and the application range is wide, and the like.