To address the low sensitivity issue of conventional silica-based photonic crystal fiber surface plasmon resonance (PCF-SPR) sensors in multi-parameter synchronous detection, a magnetic field and temperature dual-parameter PCF-SPR sensor based on ZBLAN glass is proposed to achieve high-sensitivity detection of the two parameters. A three-layer regular hexagonal air hole structure is arranged, with magnetic fluid (MF) and polydimethylsiloxane (PDMS) respectively filled into the two large air holes that are symmetric about the core and act as sensing channels, and gold nanowires are introduced into the channels to excite the SPR effect. Furthermore, the gold nanowire within the magnetic fluid channels is coated with tantalum pentoxide Ta2O5, and the influence of this configuration on mode coupling and sensing performance is investigated. The finite element method is employed to systematically analyze the effects of the air-hole diameter, hole pitch, channel diameter, gold nanowire diameter, and Ta2O5 coating thickness on the mode properties and sensing sensitivity of the sensor. The results show that the Ta2O5 coating effectively enhances the coupling between the sensor and the external magnetic field. At the magnetic field range of 30~350 Oe, the maximum magnetic field sensitivities in the x-polarization and y-polarization directions reach up to 0.877 nm/Oe and 0.9152 nm/Oe, respectively, indicating that the y-polarization is more sensitive to the magnetic field response. Within the temperature range of -10 to 80℃, the maximum temperature sensitivities of the two channels in the x-polarization direction are -2.526 nm/℃ and -1.864 nm/℃, respectively. Within the range of -10 to 30℃, the maximum temperature sensitivities of the two channels in the y-polarization direction are -3.171 nm/℃ and -1.9 nm/℃, respectively. This work provides a novel strategy for the structural design of fiber-optic sensors capable of simultaneous magnetic field and temperature measurement. The proposed sensor features a compact structure and high sensitivity, demonstrating significant potential for applications in geological exploration and marine environmental monitoring.