在初中化学里,有部分演示实验受自身条件的限制,实验效果往往不明显、不直观,不能完全发挥其教学作用。在多媒体引入演示实验后,能克服实验条件等因素的限制,提高演示实验的直观性,增加演示实验的时效性,保障演示实验的安全性,从而最大限度地发挥演示实验的教学功能。 In junior high school chemistry, some demonstration experiments are limited by their own conditions, the experimental results are often not obvious, not intuitive, can not fully play its teaching role. After introducing the demonstration experiment in multimedia, it can overcome the limitations of experimental conditions and other factors, improve the visualization of demonstration experiments, increase the timeliness of demonstration experiments, and ensure the safety of demonstration experiments, so as to maximize the teaching function of demonstration experiments.