The invention discloses a sleeve protecting core. The sleeve protecting core comprises a core body, wherein the core body is successively and coaxially provided with a core first part, a core second part, a core third part, a core forth part, a core fifth part and a core sixth part from left to right, wherein the periphery of the core fifth part is provided with a first groove in an annular manner, and four second grooves are uniformly distributed in the periphery of the core fifth part; the length directions of the second grooves are parallel to an axis of the core body, the second grooves are formed in a way that one end, which is close to the core sixth part, of the core fifth part extends towards the core forth part and can not run through the core fifth part. The sleeve protecting core has high dimensional precision and can be used for many times. The invention also discloses a processing method of the sleeve protecting core, the processing method can enable the sleeve protecting core in a stamping mould to be accurate in precision, the productive process is qualified once, and the product rejection rate is low.