Aiming at the crosstalk of temperature and strain existing in the fiber Bragg grating (FBG) sensor, we use a femtosecond laser and a phase mask to fabricate FBGs in the melting point of two heterogeneous fibers. Because temperature or strain response parameters of the FBGs are different, the simultaneous measurements of temperature and strain can be realized. Temperature and strain response parameters of two kinds of FBGs, including Yb ³⁺doped fiber with SMF-28 fiber FBGs and Er∶Yb doped fiber with SMF-28 fiber FBGs, are measured, respectively. The results indicate that the Er∶Yb doped FBG has a great difference on temperature response parameter but a similar strain response parameter with the SMF-28 fiber FBG, so the Er∶Yb doped fiber with SMF-28 fiber FBGs can be used to realize the simultaneous sensing on temperature and strain measurement. After annealing at 800 ℃, the reflectivity of Er∶Yb doped fiber FBG with SMF-28 fiber FBG can maintain a long-term stability at 700 ℃. It can be used to realize the temperature-strain dual-parameter demodulation below 700 ℃.