Among various types of continuous fibre reinforced ceramic matrix composites (CMCs), SiC fiber (SiCf)-reinforced SiC matrix composites (SiCf/SiC) with superior mechanical and thermal properties have obtained increasing attention in industrial applications like aerospace, nuclear and braking system over past few decades[1,2,3]. However, major issues like sensitivity to structural defects and brittle behavior in external load require effective solution for optimizing the performance of SiCf/SiC in application. Nanotubes-reinforced hierarchical composites introduce a practicable way to handle the issues due to their significant improvement in toughness and strength. Nanotubes such as carbon nanotubes (CNTs) and boron nitride nanotubes (BNNTs) present better mechanical properties by enhancing brittle microstructural parts relatively away from fiber bundles, monolithic composites are efficiently toughened and strengthened owning to ductile behavior like sliding, pull-out and bridging of these micro-scale counterparts of fibers[6,7]. Apart from CNT and BNNT, SiCnw and SiC whisker with high tensile modulus and strength also acquire good performance as hierarchical reinforcement in both Cf/SiC and SiCf/SiC composites owing to their restriction effect on crack propagation in and into fiber bundles.