The rapid development of scattering light modulation has led to many interesting applications in recent years. Imaging through a scattering medium and optical illusion are two of the most attractive examples, while they usually do not appear together on the same topic. Here, the inner relation between them will be further discussed, and a bifunctional scattering light modulation method that can realize scattering imaging and optical illusion is introduced. With the help of a high-resolution spatial light modulator, a highly efficient phase retrieval process and phase conjugation technique, well-designed modulation patterns are found to manipulate the scattering wavefront and realize the function of imaging through a scattering medium or optical illusion. The whole system can be completed in several seconds. Therefore, it can be done with a slow variated scattering environment for scattering imaging or a slow variated scene for dynamic optical illusion. The theory and proof of concept experiment prove the feasibility of the proposed method. The potential applications will be found in the area of imaging through turbid environments, camouflage, anti-detection, complex light modulation and so on.