Surface Plasmon Resonance(SPR) is a physical phenomenon, when the frequency and wave number of incident light coincide with the frequency of free electrons vibrating on the metal surface, then the electrons (i.e., plasma) on the metal surface absorb light energy and resonate, and its resonance wavelength changes with the refractive index of the precious metal surface, so SPR has a wide range of application needs in medical detection, environmental monitoring and other fields. Based on the principle of SPR, this work investigates the refractive index sensing characteristics of D-type highly birefringent photonic crystal fibers in detail. The current reports on PCF SPR sensors are mainly based on the establishment of theoretical models and numerical simulations. It is difficult to experimentally prepare PCF SPR sensors. According to the high birefringence photonic crystal fiber used in the experiment, the photonic crystal fiber of the simulation model is composed of five layers of air holes. The first layer of the cladding contains 2.2 μm, the diameter of the large air hole is 4.5 μm, and the polishing depth is represented by h, that is, the distance from the core of the photonic crystal fiber to the polishing surface, and the angle between the slow axis of the high birefringence photonic crystal fiber and the polishing surface is defined as the polishing direction θ. The gold film is coated on the flat polishing surface of the optical fiber to facilitate contact with the object to be measured. According to previous theoretical and experimental research, we set the thickness (t) of the gold film to 45 nm. The refractive index of the photonic crystal fiber background material and the refractive index of gold used in the simulation are given by the experimental data of linear interpolation. In order to obtain the waveguide mode of the side-polished high-birefringent photonic crystal fiber, this paper uses the finite element method commercial software COMSOL Multiphysics and sets the boundary conditions of the perfect matching layer for simulation. The refractive index of the analyte is set in the range of 1.330 to 1.400. Through finite element method modeling and simulation, the influence of polishing angle on the sensitivity of birefringence and refractive index sensing are studied in this paper. The simulation results show that when the height of the polishing surface from the fiber core is less than 1.5 times the duty cycle, the closer the polishing surface is to the core, the smaller the birefringence. As the polishing angle increases, the birefringence first increases and then decreases, and the refractive index sensing sensitivity decreases accordingly. When the polishing angle is 0 degrees and the refractive index ranges from 1.330 to 1.400, the average refractive index sensitivity of the device is as high as 3 457.14 nm/RIU. In addition, we have prepared a D-type high birefringence photonic crystal fiber SPR sensor. There is a big difference between the theoretical and experimental sensitivity values. The main reasons are: 1) The polishing surface is uneven (defects caused by air holes), which makes it difficult to completely remove the debris generated during the polishing process, which will affect the sensing performance. Performance; 2) After preparing the D-type fiber sample, the fiber is not coated in time. The D-type fiber is exposed to the air for a long time, and the dust in the air will further affect the performance of the device; 3) Although every time Before the test, the sensor will be cleaned repeatedly with ethanol, but it is difficult to completely remove the refractive index matching liquid left in the PCF air hole, which will affect the accuracy of the subsequent measurement results. For example, we tested the refractive index of 1.33 for the first time and cleaned it with alcohol. Drop 1.34 optical fiber matching liquid, because the previous liquid remains, the real value is difficult to achieve 1.34, and the calculation is still calculated according to 1.34; 4) The theoretical maximum value is under the condition that the polishing plane is parallel to the connection line of the two large air holes. The D-type high birefringence photonic crystal fiber SPR sensor was further used to test the concentration of glucose dissolved. The concentration of glucose solution increases from 0 g/dL to 10 g/dL in steps of 2 g/dL. As the glucose concentration increases, the D-type high birefringence photonic crystal fiber SPR sensor The peak wavelength of the pit of the transmission spectrum will be red-shifted. In the 0 g/dL glucose solution, the SPR resonance wavelength appeared at 578.96 nm, and when the glucose solution concentration was 10 g/dL, the SPR resonance wavelength drifted to 587.49 nm. According to the relationship between the glucose concentration and the peak wavelength of the pit of the transmission spectrum, the average sensitivity is 1.89 nm/(g/dL). The research results show that the D-shaped photonic crystal fiber SPR sensor can be applied to the fields of biology, chemistry and environmental monitoring.