A biological dual parametric sensing structure of D-type photonic crystal fiber based on surface plasmon resonance and directional coupling effects is presented in this paper. First, the surface plasmon resonance effect between the core of photonic crystal fiber and the metal film layer is used to detect the mass concentration of the biological liquid. Then, the directional coupling effect between the core of photonic crystal fiber and the defective core and the temperature-sensitive effect of the temperature-sensitive material are used as the temperature sensing mechanism to measure the ambient temperature. Finally, the photonic crystal fiber sensing structure model is established and numerically analyzed by the finite element software COMSOL Multiphysics. The results show that the mass concentration sensing based on surface plasmon resonance and temperature sensing based on directional coupling are independent of each other. The sensitivity of the sensor can reach 5.44 nm/(mg·mL^-1) in the concentration range of 34.6?186.7 mg/mL human serum albumin, and the sensitivity can reach 17.3 nm/℃ in the temperature range of 20?45 ℃.