Based on the new curriculum, the system science concept and the scientific concept, designing light experiment box, completing the secret of the primary school science shadow, the shadow of the sun, how the light propagation, light propagation will encounter obstacles, know prism, light reflection experiment and junior high school physical light linear propagation, light reflection, light refraction, dispersion of light series of exploration experiment. Primary school and junior high school all involve the linear propagation of light, light refraction and reflection experiments. On the basis of reducing the experimental error, expanding students'' thinking and improving the effectiveness of inquiry, we further analyzing how to carry out the connection teaching between primary school and junior middle school, so as to help students build scientific core concepts.