The invention relates to an integral purification device and an integral purification method for particles in rain and sewage. The device consists of three parts including a rotational flow riffling unit, a diameter change precipitation unit and an up-flow filter unit in vertical overlapped arrangement, wherein the rotational flow riffling unit comprises a rotational flow riffling tube, a water inlet pipe, a sand discharge pipe, a siphon cover, a siphon pipe, a water sealing groove, a water discharge pipe, a first perforation plate, a second perforation plate and a third perforation plate, the diameter change precipitation unit comprises a diameter change precipitation pool, the up-flow filter unit comprises a filter chamber case, a filter chamber base plate, a filter pool, filter materials and a filter water outlet. The device and the method provided by the invention have the characteristics that the particle removal efficiency is high, the blockage is avoided, the energy is saved, the efficiency is high, the water load impact capability is high, the occupied area is small, the investment and operation management cost are low, and the like. The method and the device can be widely applied to the particle purification in water discharge pipelines with greater slope and the rainfall runoff of roofs, elevated roads and the like.