The study experience of the optical parts of“Primary Physics Experiments”，an important course for college students，could be decently improved when optical simulation software can be introduced in the teaching process．Seelight software is applied in the experiment topic“measuring the magnification factor of a telescope”，by simulating the beam passways and adjusting the systematic parameters such as the lens separation and object distance，one can simultaneously observe the imaging results．Combined with on-hand operation，simulation software will provide the students with clearer apprehension of the experiment architecture and theory，which might be hardly achieved by traditional teaching techniques．Furthermore，by utilizing simulation software，students can break the limit of existing hardware and have a chance to study related topics．