The invention belongs to the field of reduction gears, provides an input suite of a cycloidal reducer and a machining method of the input suite and aims to solve the problems that an existing input suite is of a split structure, easy to damage and high in production and manufacturing cost. The input suite comprises an input shaft, the periphery of the input shaft is integrally provided with two annular protrusions in the circumferential direction, and the circle centers of the annular protrusions are arranged to be eccentric with the axis of the input shaft; the eccentric directions of the two annular protrusions are opposite to each other. According to the input suite of the cycloidal reducer and the machining method of the input suite, the input shaft, an eccentric sleeve and a bearing inner ring (equivalent to the eccentric sleeve of the input suite) are integrated, the structure is simplified, cumulative tolerance is shortened, and precision is greatly improved; due to the fact that the input suite is shrunk into a whole, an inner hole of the input suite can be enlarged, a motor shaft can directly stretch into the eccentric inner hole, the length is shortened, the size of an input end cover is further shortened, rigidity of workpieces is greatly increased, and the phenomenon of shaft breakage cannot occur anymore; nearly 30% of raw materials are saved, so that machining time is saved by 50%, cost is greatly lowered, and the blank in China is filled up.