In this study, we established a multiphysics coupling model of magnetic fluid hyperthermia (MFH), using complex magnetic permeability to solve the magnetic losses of magnetic nanoparticles (MNPs). The experiments were performed to verify the validity of numerical coupling method. The optimal treatment time (OTT) was regarded as the time required for the lowest temperature point of the tumor to attain the damage criteria. The OTT increased by about 42 s as the tumor radius increased by 1 cm, and decreased by 10 s for the increase in MNP dose per gram of tumor by 1 mg. To achieve cost-effective therapies under moderate treatment conditions, the preferable ranges of external magnetic field intensity H o and frequency f, MNP radius R and volume fraction phi are 3-11 kA/m, 200-500 kHz, 8-10 nm, and 5%-10%, respectively. It is greatly encouraged to adopt the combination of higher H-0 (8-11 kA/m) and lower f (200-300 kHz), and the conjunction of higher R and phi. There was a slight thermal damage to normal tissues due to eddy current loss. In conclusion, MFH can provide an excellent therapeutic effect for deep tumors.