A D-type photonic crystal fiber magnetic fluid double core filled magnetic field and temperature dual parameter measurement sensor structure was proposed. The resonance effect was enhanced and sensitivity was improved by narrowing the two holes in the center of the air hole in the first layer， the magnetic fluid-filled dual-core magnetic sensing channel and the ethanol-filled temperature-sensitive channel， which were introduced to achieve high-sensitivity sensing and dual-parameter sensing. The results showed that the sensor temperature was -30 ℃~50 ℃， the transmission peak temperature sensitivity was 1.239 nm/℃， and the linearity reached 0.995 7， while the loss peak temperature spectral sensitivity was 2.514 nm/℃， and the linearity reached 0.997 17. The external magnetic field was 10 mT~30 mT， the transmission peak magnetic field sensitivity was -3.799 nm/mT， the linearity was up to 0.997 27， and the temperature measurement error was 1.135%， the magnetic field measurement deviation was 6.67%， with high sensitivity， accurate measurement， compact structure and other features. This study could further optimize the design of D-type PCF-SPR dual-parameter demodulation sensor.