The invention relates to an industrial wastewater treatment system and a treatment method, in particular to treatment system and method for waste water in a chemical spinning factory. The invention mainly solves the technical problems that drainage is substandard and the water resource is not sufficiently utilized because of long treatment process, complex treatment technology and poor control inthe traditional chemical fiber spinning treatment process. The technical scheme of the invention is that the treatment system for the wastewater in the chemical spinning factory comprises a mechanical drum sieve, a photon valence-lowering device, a biological flat membrane reactor, a ball-shaped shallow sand filter and an ultrafiltration membrane filter, wherein the devices are sequentially communicated through pipelines; delivery pumps are arranged on the pipeline leading to the ball-shaped shallow sand filter from the biological flat membrane reactor and the pipeline leading to the ultrafiltration membrane filter from the ball-shaped shallow sand filter; and the biological flat membrane reactor is connected with an air blower through an aeration tube or an aeration plate. In the system,a mechanical barrier device can further be introduced on the pipeline leading to the biological flat membrane reactor from the photon valence-lowering device so as to be used for treating domestic sewage.