Linear sliding block and actuating device

A linear sliding block includes a first assembly and a second assembly. The first assembly is made of a metal material and includes a sliding body, two rolling-ball sliding rails and two rolling-ball through holes. The second assembly is made of a non-metal composite material, and the second assembly is installed on the first assembly. The two rolling-ball sliding rails are integrally disposed at two sides of the sliding body, respectively, and each of the two rolling-ball sliding rails extends along an axial direction. The two rolling-ball through holes penetrates the sliding body along the axial direction, and the two rolling-ball through holes are arranged and spaced away from each other. Hence, the process of assembling the linear sliding block can be simplified, and lightweight can be achieved while fluency of the balls rolling in the linear sliding block can be maintained.