Surface plasma resonance technology is increasingly widely used，but due to the complex preparation of sensitive units，especially the low transmission efficiency of optical fiber surface plasma resonance sensor system，such sensor experiments are difficult to carry out in undergraduate teaching．It presents a multimode- inglemode structure fiber SPＲ sensor experiment which simplifies the structure of sensitive units and improves the transmission efficiency．Through experimental measurements of water，acetone，ethanol，isopropyl alcohol and ethyl orthosilicate，the results show that the average sensitivity of the experimental device can reach the 2902 nm/ＲIU，sensitive unit，which is simple to make and has a high success rate，which is very suitable for use in undergraduate teaching．