The basic principle and structure of the extension machine for micro creeping robot driven by shape memory alloy（SMA）are introduced.The linear movement principle and the turning principle of the creeping robot are analysed and discussed respectively.Furthermore

The relationships between the step distance of the creeping robot and the currents of SMA actuators

the turn angle of the creeping robot and the currents of the SMA actuators

the response time of the creeping robot and currents of the SMA actuators are analyzed and tested detailedly.Based on the experimental results

the current of the SMA actuators is obtained.