Temperature sensor, composite piezoelectric sensor and axle box or adapter

The invention relates to a temperature sensor, a composite piezoelectric sensor and an axle box or an adapter. The temperature sensor is used for measuring the temperature of a to-be-measured object and comprises a base body, external threads are formed on the head of the base body and used for being screwed with internal threads of the to-be-measured object, and a groove is formed in the top endof the base body; the at least one metal pressing block is arranged in the groove; the first elastic element is located between the bottom wall of the groove of the base body and the metal pressing block and can be compressed in the axial direction of the base body, and it is guaranteed that the metal pressing block protrudes out of the base body to make contact with the to-be-measured object. According to the temperature sensor, the metal pressing block is automatically pressed on the to-be-measured object and the base body of the sensor by means of the first elastic element, it is guaranteedthat heat is transmitted