Due to the limited updating rate of spatial light modulator (SLM), the reported methods based on SLM can't satisfy the requirements of biological tissues endoscopic imaging in vivo. Considering the updating rate of digital micro-mirror device (DMD) is two orders of magnitude higher than the fastest SLM, a method is proposed for focusing and scanning light through a multimode fiber (MMF) based on binary amplitude modulation DMD technique. Theoretical analysis shows that there exists a quadratic function between the total light intensity within the focused region at the distal end of the MMF and the amplitude modulation coefficient of the sub-region on DMD. Thus, it can be realized that focusing and scanning light through a MMF by modifying the incident wavefront with the binary amplitude modulation DMD technique. What’s more, for a given number of modulation sub-regions, the number of iterations for this method is 1/256 of that for the phase iterative optimization methods or 1/3 of that for the optimal phase computation optimization methods with three-step phase shift. We demonstrate that focusing and scanning light in three-dimensional space through a 5 m length and 105 μm core diameter MMF with this method. The results show that the proposed method has the advantages of fast modulation speed, high algorithm reliability and good uniformity of focused spots.