A vacuum-molded and reusable limb protecting pad (A) comprises an airtight bag body (10), two locating components (17) being respectively arranged at the positions, which are spaced and correspond to each other, of two inner side surfaces of the airtight bag body (10), the locating components (17) being capable of dividing a containing space (13) in the bag body (10) into a plurality of locating spaces (131), the bag body (10) being maintained to be in a flat and narrow shape, and the adjacent locating spaces (131) being enabled to be spaced, but be communicated with each other for being filled with a plurality of granules (40); an air nozzle (20), the bottom of the air nozzle (20) being sealed on the surface of the bag body (10) in an airtight way, and the air nozzle (20) being internally provided with an air channel (211) which is used for communicating the inside and the outside of the bag body (10) and can be switched into a state of communication or non-communication; a filter screen (112), arranged at a position corresponding to the air channel (221), the sieve number of the filter screen (112) being less than the particle sizes of the granules (40); and at least one tightening component (15), capable of enabling the limb protecting pad (A) to stably surround and cling to the surface of a limb (B).