In aluminum extrusion production, the usual practice is to use a quick way to detect aluminum temperature thermocouple contact, and in the process of extrusion profiles have been movement, its detecting element must be with material movement, cannot stay online monitoring, and artificial operation technique, testing profile immediately after the mold cooling, lead to detection temperature deviation is very large, so it is difficult to get the exact temperature and speed is the best match. Temperature detection is divided into two types: contact and non-contact.