The invention relates to the technical field of sewage treatment, particularly to a sewage purification and treatment device and a method thereof. The device comprises a multifunctional reaction tank,a biochemical reaction standing tank and a filter pressing purification tank, wherein the multifunctional reaction tank, the biochemical reaction standing tank and the filter pressing purification tank are communicated in sequence, a water inlet is disposed at the multifunctional reaction tank, a water outlet is arranged at the filter pressing purification tank, the water inlet can also be disposed at the filter pressing purification tank, and the water outlet is disposed at the multifunctional reaction tank so as to flexibly realize positive and negative purification operation with differentpurification requirements. The operation method of the water treatment and purification device can optionally dispose the inlet and outlet to realize the purification treatment processes of differenttechnologies. The device disclosed by the invention realizes adaptive treatment of various water, and has high treatment efficiency, also according to the device and method provided by the invention,the structure is compact, the device floor space is small, the process can be positively, negatively and freely combined, and the treatment mode is flexible. Therefore, the device and method have wide application in the sewage treatment field.