In order to realize the possibility of a single mode fibre coupler used as a sensor, the theory of an optic fibre coupling sensor is analyzed. According to the relation that the coupler’s coupling ratio is sensitive to the coupled fused part length change and vibration frequency, a detection technology for strain and vibration parameters is proposed. The strain and vibration experimental system based on a micro-strain instrument and a cantilever is set up and its working principle is described in detail.The strain response of the fibre coupling sensor is investigated through a micro-strain test and the effects of temperature and transverse interference on the output ratio are given. Experimental results indicate that strain response of the fibre coupling sensor is excellent and the sensor temperature remains a constant in the coupling ratio range from 10% to 90%. The dynamic experiments of a piezoelectric sensor and a coupling fiber-optic vibration sensor are investigated and a 0-50 Hz low and 4 kHz high frequency responses are approved during the vibration testing. These results show that the single-mode fibre coupling sensor can measure a vibration signal practically, meanwhile,other influencing factors including the fused part materials, coupler structures and fabrication need to be resolved for engineering applications in the future.