Abstract: Provided is a 3D printing method and system using a near-infrared semiconductor laser as a heating source. The 3D printing system includes a printing spray head (4). In the 3D printing process, a laser beam is output by the near-infrared semiconductor laser to form a laser spot, which scans in an arbitrary path to cover a relevant area of a printed material for in-situ heating, thereby realizing the “asynchronous” printing mode. The near-infrared laser has higher penetration depth compared with a mid-infrared laser, so that the printing method using a near-infrared semiconductor laser as a heating source can be flexibly compatible with various printing platforms and the working process of the laser in the formed printing system can be decoupled from the 3D printing process of an article.