his paper demonstrates a highly sensitive temperature sensor based on photonic crystal fiber (PCF) to evaluate the temperature of an analyte. The proposed structure is evaluated by a finite-element method (FEM) which is composed of one silica core and an analyte core. The maximum wavelength sensitivity of 29,411.765 nm/refractive-index unit (RIU) and the maximum temperature sensitivity of 5000 pm/°C are recorded for the proposed PCF based temperature sensor. According to our knowledge, this measurement represents the maximum sensitivity response to the PCF based temperature sensor. Additionally, the temperature is tuned between 30–60 °C for getting highest sensitivity response. Besides, the peak wavelength shifts, different loss spectra are also investigated for the proposed model. In the future, this proposed structure can be used for multiple sensing purposes such as gas sensing, biomedical sensing, salinity sensing, chemical sensing with modification and analyzing upon this structure.