The temperature sensor presented herein based on microwave dielectric resonator,using alumina ceramic as substrate to survive in harsh environment.The resonant frequency of resonator is determined by the relative permittivity of alumina ceramic,which changes monotonically with elevates temperature.A rectangle aperture was etched on the surface of resonator working as both incentive and coupling device.Broadband slot antenna fed by coplanar waveguide (CPW) was utilized as interrogation antenna to wireless detects the sensor signal by using microwave-backscattering technique.Theoretical analysis,software simulation,and experiments verified the feasibility of temperature sensing system.The sensor was working in metallic environment,which cause severely interference to the extract of sensor signal.Therefore,frequency domain compensation was introduced to filter the background noise and improve the signal to noise ratio (SNR) of sensor signal.The extracted peak frequency is found to shift monotonously from 2.441GHz to 2.291GHz when the temperature changes from 27°C to 800°C,leading to an average absolute sensitivity of 0.19MHz/°C.