The experiment circuit is divided into two parts: fixed and non-fixed in a synthetical teaching experiment for SCM.The fixed part is made of printed circuit board in its auxiliary device, the non-fixed part is lapped on the bread board by the experimenters .Above contents include:(1) system storage structure is non fixed, which using the jumper switch K1, the system structure may become the Princeton structure, or Harvard architecture or no RAM structure;(2) system storage capacity is non fixed, which using the jumper switch K1,K2, the chip EPROM or RAM is arbitrarily selected by experiment system according to the needs. Experiences show: this auxiliary device improves the flexibility and versatility,saves time, strengthens the experimenter’s operational ability and improves the success rate for the SCM experiment.