A dust collector for electric hammer is disclosed, including a fixed pipe fixedly installed in an opening position, a movable pipe fixedly installed with the electric hammer, and a collection container for collecting dust. A front end of the fixed pipe has a cover body for covering the opening position externally and a drill hole for inserting a drill of the electric hammer, and the drill hole is connected to an interior of the cover body. A front end of the movable pipe is connected to a rear end of the fixed pipe, and the movable pipe is configured to perform a back and forth stretching activity in parallel with a direction of the drill hole with respect to the fixed pipe. The collection container is fixed at a rear end of the movable pipe to connect with the movable pipe.