The invention belongs to the technical field of cement-base sound-absorbing materials, and relates to a cement-base sound-absorbing material for tunnel wall surfaces and a preparation method thereof. The cement-base sound-absorbing material for tunnel wall surfaces comprises the following raw materials in parts by mass: 100 parts of expanded vermiculite, 100-160 parts of cement, 100-160 parts of fly ash, 0.1-0.2 part of air entraining agent, 1-3 parts of thixotropic agent, 3-5 parts of redispersible latex powder and 0.5-1 part of polypropylene fiber. The cement-base sound-absorbing material for tunnel wall surfaces can be prepared into a dry mixture, and is environment-friendly. The cement-base sound-absorbing material for tunnel wall surfaces can be mixed with water on site and sprayed on the tunnel wall surface, and thus, is convenient for construction. The cement-base sound-absorbing material for tunnel wall surfaces is mainly composed of expanded vermiculite and foaming cement with excellent fire resistance, and thus, has favorable fire resistance; and the combustion performance can reach Grade A. The noise reduction coefficient (NRC) is greater than or equal to 0.60, and the cement-base sound-absorbing material for tunnel wall surfaces has favorable sound absorptivity. The material can form a hard sound-absorbing material, and has the advantages of disturbance resistance and favorable weather resistance.