Carbon matrix/Carbon fibre reinforced composite(C/C composite) has many special characteristics such as high strength, high elastic modulus, high temperature resistance and ablation resistance. So it is used to manufacture rocket engine nozzle in aerospace filed. But its security will be seriously effected during rocket engine working due to the manufacturing defects. Based on analyzing defect types and structure characteristic of C/C composite, the ultrasonic and infrared testing methods on C/C composite are further studied in this thesis. And effective defect detection has been achieved.