The invention relates to robot drivers, in particular to a machining and assembling method for an intelligent care robot speed reducer. The method includes the steps that stop pieces are arranged at one end of an inner shaft and one end of an outer hollow shaft in an interference assembly mode; assembly holes are formed in two elliptical driving wheels through machining correspondingly; then a flat-bottom annular groove is formed in the circumferential direction in the middle position of the axial direction of a flexible gear green body through turning; an annular V groove is formed in the circumferential direction in the bottom of the flat-bottom annular groove through machining; two rows of outer teeth are machined at the positions, on the two sides of the annular groove, of the periphery of the flexible gear green body correspondingly; and finally, the two elliptical driving wheels provided with the inner shaft and the outer shaft are mounted inside a flexible gear, the two elliptical driving wheels align to the two rows of outer teeth correspondingly, and in the end, the elliptical driving wheels and the flexible gear which are assembled well are mounted to a rigid gear inner ring on which two rows of inner teeth are formed. According to the machining and assembling method for the intelligent care robot speed reducer, an inner shaft and outer shaft mounting mode is adopted, two kinds of driving power can be provided, and the transmission ratio of the speed reducer and the like can be changed; and meanwhile, on the aspect of machining and assembly, the elliptical driving wheels are fixed through ring springs, so that the friction force is better reduced and the elliptical driving wheels are prevented from being damaged.