Silicon nitride ceramic pipes were prepared by extrusion with carboxymethyl cellulose (CMC) as the binder. The effect of binder content on the performance of green ceramic pipes was studied. The effect of sintering temperature on the relative density, flexural strength and microstructure of silicon nitride ceramics was studied. At the same time, the high temperature strength performance of silicon nitride ceramics was studied. The results show that with the binder content of 7% (mass fraction), the green ceramic pipe can dry and shrink evenly, and the surface is smooth without micro-cracks. At the sintering temperature of 1 740 ℃, the bulk density and flexural strength of silicon nitride ceramics reach the maximum value, which are 96% and (684±23) MPa, respectively. And the flexural strength reaches (380±21) MPa at 1 200 ℃, silicon nitride ceramics show a good high temperature strength performance.