The invention provides a method and a system for quickly drawing an indoor preview map, which provide an online, visual 3D graphic editing tool to enable a designer to quickly edit a customer's housetype through a browser and quickly obtain a high-quality effect map. At a client, the room type is identify by importing a house type diagram to the cloud end and the sample room in a 3D template library is called up, after the client is read by the sample room, various parameters are set according to the room type and submitted to the cloud, and high-quality rendering services are provided for the client through the cloud, the computing resources are allocated to each rendering task more efficiently, and the results are sent back to the client for use after completion. Meanwhile, the simplified model is used for real-time design and rendering, which ensures smooth user experience, efficiently allocates computing resources to each rendering task, and then transmits the results back to theclient for use.