In order to reduce the error caused by temperature in the magnetic field measurement system based on magnetic fluid (MF) and long period fiber grating(LPFG), a magnetic field measurement correction scheme based on MF and banded twin-core optical fiber is proposed. The LPFG with different cladding thermo-optic coefficients is integrated in the ribbon twin-core optical fiber, and the difference between the temperature sensitivity is used to correct the magnetic field measuring results. Through theoretical analysis and system simulation, the temperature characteristics of MF and LPFG are demonstrated, and the relationship between MF refractive index and LPFG resonant wavelength in a certain temperature range is revealed. Compared with the system without temperature compensation, the proposed scheme's intensity to accuracy is increased by at least 79.1%.