Weft yarn detection device in air-jet loom

The invention relates to a weft yarn detection device in an air-jet loom. A weft yarn detection sensor of the weft yarn detection device in the air-jet loom comprises a support member, a light-emitting optical fiber and a light-receiving optical fiber, the support member is configured to face a weft yarn path for a weft yarn, the light-emitting optical fiber and the light-receiving optical fiber are disposed in the support member, and then end surfaces of the light-emitting optical fiber and the light-receiving optical fiber face the weft yarn path. The end surface of the light-emitting optical fiber comprises a first surface region and a second surface region, and the second surface region is away from the end surface of the light-receiving optical fiber. The end surface of the light-receiving optical fiber comprises a first surface region and a second surface region, and the second surface region is away from the end surface of the light-emitting optical fiber.