Abstract: To overcome the problems in spectrometer experiments, an attempt of DIY teaching mode is employed. It is carried out as follows: Firstly, an assignment of improvement is given to students in advance, encouraging them to use different techniques, “Learning by doing, doing by learning”; Then, the students should do the experiment with auxiliary unit made by themselves, accompanying with some activities of communications and appraisals. Actually, enthusiasm of students and results in teaching are all greatly improved in this way. It is worth to recommending that built-in laser auxiliary unit and USB camera auxiliary observation system, which has the advantages of convenient fabrication and intuitive phenomenon, can improve adjustment and demonstration of spectrometer experiments well.