A series ternary composites of poly(ethylene oxide)/ionic liquid 30/70 (P30) with different contents of uniformly dispersed halloysite nanotubes (HNTs) were prepared. Rheological and phase separation behavior in the homogeneous and two-phase regions were further investigated. In the single-phase region of P30, a relatively lower percolation threshold about 3 wt% of HNTs loading is determined by Cole-Cole plots. For composites with HNTs concentration beyond the threshold, the steady shear flow exhibits two shear-thinning regions due to the coupled relaxation of HNTs network and polymer entanglement. Even though the presence of HNTs can hardly change the phase transition temperature of P30, the phase separation kinetics is significantly retarded due to the location of HNTs in the PEO-rich phase impeding the escaping of ionic liquid (ILs) from PEO phase. During time sweeps, the inconsistent deviation of the storage modulus G with the increase of HNTs loadings in the two-phase region can be ascribed to the competitive effect that contribution of HNTs to the elasticity of the system and leading to reducing the phase interface.