The phase, microstructure and properties of mulit-core cermets based on (Ti,W,Ta)CN and TiCN powders were investigated in sintering process. According the analyses of X-Ray diffraction (XRD) and scanning electron microscope (SEM), it indicated that the sintering behavior of the multi-core cermet in sintering process could be divided into three stages: (I) pre-densification stage (the sintering temperature < 1200 °C); (II) rapid densification stage (the sintering temperature between 1200 °C and 1350 °C); (III) final densification stage (the sintering temperature > 1350 °C). Meanwhile, the evolution of η-phase in multi-core cermet was discussed as well. Furthermore, the microstructural and chemical information of η-phase were studied by Transmission Electron Microscopy (TEM) using X-ray energy dispersive spectrometry (XEDS) and selected area electron diffraction (SAED). The thickness of the rim structure would increase with the rise of sintering temperature, while the mechanical properties of the material would firstly increase then decrease with the rise of sintering temperature, and achieve the highest transverse rupture strength at 1450°C, the highest hardness at 1390°C.