According to the micro-structure of 2.5-D self-healing C/SiC composite, a tensile mechanical model in weft and warp directions were established based on the damage mechanism including interfacial crack and matrix crack. The tensile nonlinear stress-strain functions in weft and warp directions were gained, and the predicted stress-strain curve agreed with the experiment very well. The result shows that,the largest error of the predicted stress-strain curve in weft direction is 8% to 9%. The largest error of the predicted stress-strain curve in warp direction is 10%. The stress-strain curve in weft direction is different from that in warp direction. By adopting tangent elasticity modulus and average crack distance, mass work to obtain strain is not needed and the model is simplified.