In container-based virtualization, the mainstream way to build images is Dockerfile. However, using Dockerfile to build images has the obvious deficiency:Because of complexity of the Dockerfile syntax, the way of editing with text does not provide effective guidance of syntax, and effective detection for common errors, which lead to low efficiency in building images. In addition, using the 3rd party images with no complete explanation, users can not completely understand the usage of images and security is also a challenge for the 3rd party images, this bring the difficulty to reuse images. To solve the above problem, based on analysising syntax of Dockerfile, statisticsing and analysising common errors and deeply studying on storage mechanism of Docker image, we design a tool for building Docker image on Dockerfile, which using technology of visual editing, error detection and reverse engineering. In view of the problems existing in building images, the tool can provide effective syntax guide, and detect the common errors effectively. In addition, in order to verify the usage and safety of the third party images, by reversing images to Dockerfile, users can fully understand usage of the third party images via Dockerfile, and through the way of second build, the tool can solve problem of safety of the third party images partly.